Dissenting Opinion by
Justice CASTILLO.The majority fixes jurisdiction and venue in Cameron County, concluding that Cameron County is the only proper venue for enforcement of the claims of appellant, Tommy Wayne Fleming. Respectfully, I conclude that the majority’s decision ren*719ders illusory1 the unambiguous written agreement2 that authorized enforcement in Bexar County. Consequently, I respectfully dissent.
The agreed-to clause unequivocally authorizes Fleming to enforce, in particular, the confidentiality clause in a court of competent jurisdiction in either Cameron or Bexar County. The clause could not more plainly authorize Fleming to select the county in which to litigate. More importantly, the clause states, in pertinent part, that appellee Patricio Ahumada “specifically waives any right to transfer venue in the event litigation ensues.” Litigation ensued. By the express terms in the clause, Ahumada agreed that a dispute would be litigated in Cameron County if Fleming, at his sole discretion, chose to litigate there. Fleming exercised his sole discretion not to litigate in Cameron but, rather, in Bex-ar County. The parties did not agree as to proper venue. They did agree that Ahumada waived any right to transfer venue. By allowing Ahumada to challenge and prevail on the very grounds he agreed to waive, the majority renders his promise and the agreement illusory.
I am mindful that the plaintiff has the first choice to fix venue in a proper county by filing the suit in the county of its choice. In re Masonite Corp., 997 S.W.2d 194, 197 (Tex.1999) (orig.proceeding). A plaintiffs choice of venue stands unless challenged by proper motion to transfer venue. See Tex.R. Civ. P. 86(1); In re Missouri Pac. R.R. Co., 998 S.W.2d 212, 216-17 (Tex.1999). If the plaintiffs venue choice is not properly challenged through a motion to transfer venue, the propriety of venue is fixed in the county chosen by the plaintiff. Wilson v. Texas Parks & Wildlife Dep’t, 886 S.W.2d 259, 260 (Tex.1994); see Tex. Civ. Prac. & Rem.Code Ann. § 15.063 (Vernon 2002); Tex.R. Civ. P. 86(1). Because he unambiguously agreed to waive any right to transfer, Ahumada consented to litigate in Bexar County. His challenge to venue in that county was improper because he expressly waived that right.
In sum, by his eighth issue, Fleming asserts that the trial court erred in denying his motion to transfer venue. I would sustain the issue. The enforcement clause here unambiguously meant what it said: Fleming would decide the county and Ahu-mada waived the right, if any, to complain. Nothing within the clause itself made the clause ambiguous. Accordingly, I would enforce the parties’ unambiguous agreement. Because the majority and I diverge as to the validity of the parties’ agreement, including Ahumada’s waiver, my dissent as *720to the remaining issues is not necessary to the final disposition of the appeal. Thus, respectfully I do not address them. See Tex.R.App. P. 47.1.
. A promise is illusory when it fails to bind the promisor, who retains the option of discontinuing performance. See Light v. Centel Cellular Co. of Tex., 883 S.W.2d 642, 645 (Tex.1994); In re H.E. Butt Grocery Co., 17 S.W.3d 360, 370 (Tex.App.-Houston [14th Dist.] 2000, no pet.). When illusory promises are all that support a purported bilateral contract, there is no mutuality of obligation and, thus, there is no contract. In re C & H News Co., 133 S.W.3d 642, 647 (Tex.App.-Corpus Christi 2003) (original proceeding).
. If there is no ambiguity, the construction of the written instrument is a question of law for the court. City of Alton v. City of Mission, 164 S.W.3d 861, 869 (Tex.App.-Corpus Christi 2005, pet. filed) (citing City of Pinehurst v. Spooner Addition Water Co., 432 S.W.2d 515, 518 (Tex.1968)). It is the general rule of the law of contracts that where an unambiguous writing has been entered into between the parties, the courts will give effect to the intention of the parties as expressed or as is apparent in the writing. Id. In the usual case, the instrument alone will be deemed to express the intentions of the parties for it is objective, not subjective, intent that controls. Id. The primary concern of a court interpreting a contract is to ascertain and to give effect to the intentions of the parties as expressed in the instrument. Id. (citing R & P Enter. v. LaGuarta, Gavrel & Kirk, 596 S.W.2d 517, 518 (Tex.1980)).