A general court-martial with enlisted representation convicted the appellant, contrary to his pleas, of willful dereliction of duty, aggravated sexual assault, and assault consummated by a battery, in violation of Articles 92, 120, and 128, Uniform Code of Military Justice, 10 U.S.C. §§ 892, 920, and 928. The approved sentence was to confinement for 15 months, reduction in pay grade to E-l, total forfeiture of pay and allowances for a period of 18 months, and a bad-conduct discharge.
The appellant raises five assignments of error. First, he alleges that his conviction under Article 120, UCMJ, must be set aside because the statute unconstitutionally required him to disprove an element of the offense before he could raise a defense to the charge. Second, the appellant asserts that the military judge abused his discretion by denying a defense challenge for cause against Colonel (Col) T. Third, the appellant avers that the evidence of the willful dereliction of duty specification was legally and factually insufficient. Fourth, the appellant alleges that the military judge abused his discretion when he failed to suppress the appellant’s “involuntary” statement to investigators. Finally, the appellant asserts that the military judge abused his discretion when he failed to suppress evidence of a “pretext telephone call.”1
We have examined the record of trial and the pleadings of the parties. We conclude that the findings and sentence are correct in law and fact and that no error materially prejudicial to the substantial rights of the appellant was committed. Arts. 59(a) and 66(c), UCMJ, 10 U.S.C. §§ 859(a) and 866(c).
Background
The appellant, a staff sergeant (pay grade E-6), and the victim, then a lance corporal (pay grade E-3), met in early July 2007. The appellant and the victim became “friendly acquaintances” over time. Several weeks after their first meeting, the appellant made a sexual advance towards the victim which she rebuffed. Record at 232-33. The victim expressed her disapproval of the incident during a telephone conversation with the appellant later that night. The appellant apologized and indicated that it would not happen again. The victim testified that she took him at his word. Several weeks later, the appellant asked if he could come to the victim’s house to watch a movie with her. The victim agreed, only to have the appellant make yet another unwelcome sexual advance. Id. at 236-37.
After the second incident, the victim continued to interact with the appellant on nonsocial matters but made an effort not to be alone with him. On 7 October 2007, the victim hosted a barbeque at her residence. During the course of the event, the victim became extremely inebriated and was taken up to her room by friends. Shortly after being laid out on the bed, at that point fully clothed, the victim “passed out.” The victim’s friends left the bedroom door open and periodically checked on her.
The appellant arrived later that night. After being informed that the victim was in her room, he entered her bedroom. At some point after the appellant entered the victim’s bedroom, several of her friends became concerned for her safety and went upstairs only to find the previously open bedroom door closed and locked. They managed to gain entry and found the appellant sitting on the side of the bed. The victim was passed out on the bed. Her breasts were exposed and her underwear had been put on backwards. When the victim’s friends demanded an explanation, the appellant denied any wrongdoing.
The appellant later stated to Naval Criminal Investigative Service (NCIS) investigators that he found the victim asleep on her bed, woke her up and that she hugged and kissed him. He stated that she asked him to close the door and he did so. He acknowledged that when he returned to the bed, the *589victim was again passed out. He then proceeded to disrobe her, kiss her breasts and neck, and insert his finger into her vagina. The appellant acknowledges that the victim then awoke and pushed his hand away from her vagina. When asked if the victim gave him consent for the touching he initially stated that she had consented but later admitted, “No, she did not. She was passed out.” Prosecution Exhibit 1.
The victim testified that she had no recollection of the appellant being in her room before she awoke and pushed his hand away from her vagina.
At trial, the military judge instructed on the defenses of consent and mistake of fact as to consent. Additional background necessary to resolve the assigned errors is included below.
Part I. Constitutionality of Article 120, UCMJ
The appellant asserts that Article 120, UCMJ, violates his due process rights by requiring him to disprove an element of the offense before he can raise a defense to the charge, and that, the law, as applied in this case, resulted in his being convicted by a quantum of proof that was less than beyond a reasonable doubt. We will first assess the facial challenge, and then review the law, as applied in this case.
As a preliminary matter, we conclude that the military judge was required to instruct the panel on the affirmative defense of consent and mistake of fact as to consent since the “record contains some evidence of the affirmative defense[s] ... to which the military jury may attach credit if it so desires.” United States v. DiPaola, 67 M.J. 98, 99 (C.A.A.F.2008) (citations and internal quotation marks omitted).
A. Facial Challenge
The appellant contends that his conviction under Article 120(c)(2) must be set aside because the statute requires him to disprove the “substantial incapacity” element of the offense before he can raise the affirmative defense of consent. This burden shift, the appellant contends, violates his constitutional due process rights. We review the constitutionality of statutes de novo. United States v. Disney, 62 M.J. 46, 48 (C.A.A.F.2005).
Subsequent to the appellant filing his brief, this court decided United States v. Crotchett, 67 M.J. 713 (N.M.Ct.Crim.App.2009), rev. denied, 68 M.J. 222 (C.A.A.F.2009). In Crotch-ett, we considered a similar facial challenge to Article 120(c)(2)(C), UCMJ, and determined that the statute does not unconstitutionally shift the burden of proof to an accused to disprove an essential element of the offense that the victim was “substantially incapable of communicating unwillingness to participate in the act,” when an accused asserts the affirmative defense of consent. Id. at 715-16. We note that Crotchett involved a Government appeal under Article 62, UCMJ, 10 U.S.C. § 862, and that at the time of our decision, no specific evidence had been presented. We expressly did not decide whether the statute was unconstitutional as applied.
Following Crotchett, we conclude that the elements of Article 120(c)(2) are distinct from the affirmative defenses of consent and mistake of fact as to consent. Id. at 713. The Government is not required to prove the putative victim’s “lack of consent,” but instead, need only prove the victim was “substantially incapacitated.” Arts. 120(c)(2), (t)(14)-(16), UCMJ. Similarly, the appellant, in asserting the affirmative defense of consent, is not required to prove capacity.
As a matter of law, the affirmative defense of consent is unavailable where the putative victim is “substantially incapacitated,” regardless whether the victim used “words or overt acts indicating a freely given agreement to the sexual conduct at issue by a competent person.” Arts. 120(c)(2), (t)(14), UCMJ. However, the statute provides an alternative affirmative defense in such a scenario, mistake of fact as to consent, if the accused reasonably and honestly held, “as a result of ignorance or mistake an incorrect belief that the [putative victim] consented” through words or deeds to the sexual conduct at issue. Art. 120(t)(15), UCMJ.
As Article 120(c)(2), requires no assignment of burdens that would deprive an accused of his right to due process under the *590Fifth Amendment, we conclude that the statute is not facially invalid. Crotchett, 67 M.J. at 716; see also United States v. Neal, 67 M.J. 675, 681-82 (N.M.Ct.Crim.App.2009), certificate of review filed, — M.J. - (C.A.A.F. 15 May 2009).
B. As Applied Challenge
The appellant asserts that Article 120(t)(16), as applied through the military judge’s instructions, “resulted in [his] being convicted of an offense by a quantum of proof that was less than beyond a reasonable doubt.” Appellant’s Supplemental Brief of 29 Sep 2009 at 3-8. He argues that in order to instruct that the Government had the burden of disproving consent, “the military judge must have found” that the defense had met their burden of proving the affirmative defense of consent by a preponderance of the evidence. Id. at 8-9 (emphasis in original). He further argues that it “would be nearly impossible [ ] to articulate specific injury that arose from the denials of his right to due process,” therefore the error should be analyzed as structural in nature. Id. at 10-11.
1. Instructions on the affirmative defense of consent
Prior to deliberations on findings, the military judge instructed the members “on the law to be applied in this case.” Record at 454. His instructions on the affirmative defense of consent included:
The evidence has raised the issue of whether [the victim] consented to the sexual acts concerning the offense of aggravated sexual assault....
Consent is a defense to that charged offense ....
The prosecution has the burden to prove beyond a reasonable doubt that consent did not exist. Therefore, to find the accused guilty of the offense of aggravated sexual assault ... you must be convinced beyond a reasonable doubt that, at the time of the sexual acts alleged, [the victim] did not consent.
Id. at 456-57.
Article 120 allocates burdens, with respect to the affirmative defense of consent, as follows: “The accused has the burden of proving the affirmative defense by a preponderance of the evidence. After the defense meets this burden, the prosecution shall have the burden of proving beyond a reasonable doubt that the affirmative defense did not exist.” Art. 120(t)(16), UCMJ.
2. Principles of Law
“The military judge bears the primary responsibility for ensuring that mandatory instructions ... are given and given accurately.” United States v. Miller, 58 M.J. 266, 270 (C.A.A.F.2003); see also Rule for Courts-Martial 920(e), Manual for Courts-Martial, United States (2008 ed.). A military judge’s “[f]ailure to provide correct and complete instructions to the panel before deliberations begin may amount to a denial of due process.” United States v. Wolford, 62 M.J. 418, 419 (C.A.A.F.2006).
“It is well established that when the statute’s language is plain, the sole function of the courts — at least where the disposition required by the text is not absurd — is to enforce it according to its terms.” Neal, 67 M.J. at 678 (quoting Lamie v. United States Trustee, 540 U.S. 526, 534, 124 S.Ct. 1023, 157 L.Ed.2d 1024 (2004)) (citations and internal quotation marks omitted). While courts are required to construe statutes to avoid constitutional questions, this canon does not license a court to usurp the policymaking and legislative functions of duly elected representatives. Heckler v. Mathews, 465 U.S. 728, 741-2, 104 S.Ct. 1387, 79 L.Ed.2d 646 (1984).
Erroneous instruction on an affirmative defense has constitutional implications, and “must be tested for prejudice under the standard of harmless beyond a reasonable doubt.” Wolford, 62 M.J. at 420 (quoting United States v. Kreutzer, 61 M.J. 293, 298 (C.A.A.F.2005)). “The inquiry for determining whether constitutional error is harmless beyond a reasonable doubt is whether, beyond a reasonable doubt, the error did not contribute to the defendant’s conviction or sentence.” Id. (citations and internal quotation marks omitted).
*5913. Analysis
a. Appellant’s Argument
The appellant’s argument that “the military judge must have found that [he] had already satisfied his burden of proving that [the victim] consented by a preponderance of the evidence” rests on the premise that the military judge faithfully tracked through the statutory decision process for proving affirmative defenses outlined in Article 120. Appellant’s Supplemental Brief at 8 (emphasis in original). However, this does not appear to have been the case.
The record contains no evidence that the military judge made any interlocutory determination with respect to the statutory requirement that the appellant prove the existence of the affirmative defense of consent by a preponderance of the evidence. On the contrary, it appears that the military judge instructed the members on the affirmative defense of consent because the record included some evidence of consent, as he was required to do.
We also reject the appellant’s argument that, to the extent the military judge erred in instructing the members on the defense of consent, such error constitutes a structural defect and requires mandatory reversal. See Arizona v. Fulminante, 499 U.S. 279, 310, 111 S.Ct. 1246, 113 L.Ed.2d 302 (1991); see also United States v. Meek, 44 M.J. 1, 6 (C.A.A.F.1996)(discussing per se reversal rule).2 Erroneous instruction on an affirmative defense has constitutional implications, and “must be tested for prejudice under the standard of harmless beyond a reasonable doubt.” Wolford, 62 M.J. at 420 (citation omitted).
We conclude, therefore, that the appellant’s argument has no merit.
b. Issue on Appeal
The military judge’s instructions on the affirmative defense of consent departed from the plain language of the statute by omitting the initial allocation of burdens prescribed by statute — the appellant’s burden of proving the affirmative defense of consent by a preponderance of the evidence. Art. 120(t)(16), UCMJ. The military judge’s instructions also misstated the second allocation of burdens.3
Given these instructions, the issue on appeal is whether the military judge’s instructions omitting the appellant’s statutorily prescribed burden constitutes an error that may amount to a denial of due process, or a legitimate exercise of judicial discretion. See Wolford, 62 M.J. at 419; R.C.M. 920(e)(3).
Clearly, the military judge’s instructions omitted the appellant’s burden of proving the affirmative defense of consent by a preponderance of the evidence. Although the record provides no insight into his rationale for instructing the members in this manner, the instruction provided does mirror the Military Judges’ Benchbook’s recommended members instruction on the affirmative defense of consent. Military Judges’ Benchbook, Dept. of the Army Pamphlet 27-9 (15 Sep 2002), Approved Interim Update “Article 120”, 3-45-5 “Aggravated Sexual Assault,” Note 9. It is also notable that the appellant’s burden, omitted by the military judge, was a central component of the recent, substantial revision of Article 120. Neal, 67 M.J. at 678-80.
Under the circumstances present here however, we need not determine whether these instructions constituted error, or a le*592gitimate exercise of judicial discretion, as the instructions, in either event, inured to the appellant’s benefit.
With respect to potential prejudice, the appellant has not articulated any prejudice attributable to these instructions, and we find none. The military judge’s instruction to consider the defense of consent effectively relieved the appellant of his statutorily mandated burden to prove the affirmative defense of consent, by a preponderance of the evidence, and advanced the members consideration along the statutorily prescribed scheme. In addition, the military judge’s instruction effectively burdened the prosecution with proving, beyond a reasonable doubt, that the victim did not consent to the sexual activity.
Notwithstanding the aforementioned benefits to the appellant, the members concluded, beyond a reasonable doubt, that the victim was incapacitated at the time of the incident and that she did not consent to the sexual activity. They similarly concluded either that the appellant did not mistake the victim’s words or actions for consent or that if he did make such a mistake, the mistake was not objectively reasonable.
Even assuming the military judge’s instructions on the affirmative defense of consent constitute error, those instructions not only failed to prejudice the appellant, but actually inured to his benefit by alleviating him of any burden of production or proof with respect to the affirmative defense of consent.
Moreover, the evidence of guilt in this case was overwhelming. The appellant admitted committing the sexual conduct in issue to the victim, to a mutual friend, and to the NCIS, prompting the civilian defense counsel to concede “[tjhere probably is no question that the evidence [shows that the appellant] engaged in sexual acts.” Record at 446. With respect to whether the victim was substantially incapacitated, the remaining element, the victim’s testimony, as corroborated by her friends and the appellant’s admissions to her, to a mutual friend, and to the NCIS, establishes that she was substantially incapacitated at the time of that sexual conduct.
Accordingly, we are convinced beyond a reasonable doubt that the instructions “did not contribute to the [appellant’s] conviction or sentence.” Wolford, 62 M.J. at 420; see also DiPaola, 67 M.J. at 102-03.
Part II. Challenge for Cause
The appellant contends that the military judge abused his discretion by denying the defense’s challenge for cause of Col T and that his presence on the panel raises the issue of implied bias. At trial, citing R.C.M. 912(f)(l)(N), the defense challenged Col T. Record at 175-76. Following the military judge’s denial of that challenge, the defense did not exercise a peremptory challenge on any member. Id. at 188.
Failure to exercise a peremptory challenge against any member constitute^] waiver of further review of an earlier challenge for cause, therefore, this issue is without merit. See R.C.M. 912(f)(4); United States v. Leonard, 63 M.J. 398, 403 (C.A.A.F. 2006).
Part III. Dereliction of Duty — Legal and Factual Sufficiency
The appellant asserts that the Government’s evidence was legally and factually insufficient to establish that he was willfully derelict in his duties by engaging in a relationship with the victim. His argument is two-fold: (1) that the Government failed to establish the existence and nature of a Marine Corps custom that gave rise to the duty, and (2) even assuming such a duty exists, that his conduct was not prejudicial to good order and discipline or service discrediting. This Court reviews evidence for both legal and factual sufficiency. United States v. Turner, 25 M.J. 324, 324 (C.M.A.1987). The tests are well-known.
“A duty may be imposed by treaty, statute, regulation, lawful order, standard operating procedure or custom of the service.” Manual FOR CouRts-MáRtial, United States (2005 ed.), Part IV, ¶ 16c(3)(a). “A person is derelict in the performance of duties when that person willfully [or intentionally] fails to perform [their] duties.... ” Id. at ¶ 16c(3)(c).
At trial, Sergeant Major (SgtMaj)H, USMC, testified as an expert witness about *593Marine Corps customs concerning interaction between noncommissioned officers and subordinates, and the Government introduced two regulations precluding relationships between enlisted personnel that are unduly familiar and do not respect differences in grade or rank. Record at 277-90; PEs 4, 5.
SgtMaj H testified that the customs of the Marine Corps and the aforementioned regulations preclude a staff noncommissioned officer from being on a first-name basis with an E-3, attending private gatherings, requesting and accepting a personal loan, kissing or inappropriately touching, or pursuing a sexual encounter with subordinates. According to SgtMaj H, these duties exist even if the subordinate and the noncommissioned officer are not in the same chain of command.
In this case, the appellant knew that the victim was an E-3 before meeting her. Record at 382. With knowledge of her rank, he initiated or participated in each of the aforementioned acts over a three-month period.
Considering the evidence adduced at trial in the light most favorable to the Government, we find that a reasonable trier of fact could have found the elements of the offense beyond a reasonable doubt. Turner, 25 M.J. at 325. In addition, after weighing all the evidence in the record of trial and recognizing that we did not see or hear the witnesses, this court is convinced of the appellant’s guilt beyond a reasonable doubt. Id.; see also Art. 66(c), UCMJ.
We find the appellant’s fourth and fifth assignments of error to be without merit. See United States v. Matias, 25 M.J. 356, 361 (C.M.A.1987).
Conclusion
The findings and approved sentence are affirmed.
Chief Judge GEISER, Senior Judges VINCENT and MITCHELL, and Judges PERLAK and CARBERRY concur.. The final two assignments of error were raised pursuant to United States v. Grostefon, 12 M.J. 431 (C.M.A.1982).
. See generally Neder v. United States, 527 U.S. 1, 9, 119 S.Ct. 1827, 144 L.Ed.2d 35 (1999)("an instruction that omits an element of the offense does not necessarily render a criminal trial fundamentally unfair”); Yates v. Evatt, 500 U.S. 391, 402, 111 S.Ct. 1884, 114 L.Ed.2d 432 (1991) (constitutionally erroneous instruction shifting the burden of proof subject to harmless-error review); Pope v. Illinois, 481 U.S. 497, 504, 107 S.Ct. 1918, 95 L.Ed.2d 439 (1987) (harmless-error analysis appropriate, even though trial court improperly instructed the juiy on an element of an obscenity charge); Rose v. Clark, 478 U.S. 570, 576, 106 S.Ct. 3101, 92 L.Ed.2d 460 (1986)(harmless-error inquiry appropriate where jury incorrectly instructed on the element of malice in a murder trial).
. Though not raised or essential to resolution of this appeal, the military judge also deviated from the plain language of the statute by placing the burden on the Government to prove beyond a reasonable doubt that the putative victim "did not consent” vice "that the affirmative defense [of consent] did not exist." Id. at 456-57.