concurring. I concur in the Court’s result but for a different reason. I suspect that a modification-of-custody proceeding *105is made more confusing given the two-prong test so often enunciated in the case law. The rubric of bifurcation surrounding the “modification” process is illusive generally and even more so in a case like this. The Court’s twists and turns through it today does not help resolution of the dispute.
It would be preferable to decide a motion to modify by merging the jurisdictional “threshold hurdle” of Kilduff v. Willey, 150 Vt. 552, 553, 554 A.2d 677, 678 (1988), with the best interest test. After all, it is impossible to evaluate “real, substantial and unanticipated-change of circumstances” without considering how the events and circumstances impact on the child’s best interests.
That observation made, I depart from the Court’s point of view and focus rather on the trial court’s analysis, with which I agree. If the mother here had been the unconditional legal custodian (the parent with sole legal rights and responsibilities), Lane v. Schenck, 158 Vt. 489, 614 A.2d 786 (1992), would control. The mother’s decision to move with the children to Pennsylvania would be entitled to deference and, even though the mother’s reason for the move was exceedingly weak, her decision to move might have been — as the dissent so persuasively argues — protected under the standard announced in Lane.
In this appeal, however, we are not dealing with the usual sole custody situation. Mother’s custody was conditioned by a stipulation:
If either party moves more than fifty (50) miles from their current homes in Thetford and Norwich, it shall constitute a change in circumstances so that the Court may reconsider existing parental responsibilities and visitation.
The trial court stated:
The financial, education, housing, and co-parenting plans agreed upon by the parties all had as a central element that Ms. DeBeaumont would be residing in the marital home in Thetford and that Mr. Goodrich would be living in close proximity to her.
The trial court held:
In this case, Ms. DeBeaumont [had], by the Court’s order, sole parental rights and responsibilities. However, in reality the parties had shared parental rights and responsibilities since the separation ....
It was the parenting arrangement that gave the children’s lives stability, not the designation of one as having sole parental rights and responsibilities.
(Emphasis added.)
*106In essence, then, the mother’s move reopened the custody question as if it were governed by the usual considerations in awarding custody and was not governed by the more rigorous standard demanded in Lane.