Ordered that the order is affirmed, with costs.
It is well settled that in cases where a change of custody is sought, the relief should be granted when, in the court's discretion, "the totality of the circumstances * * * warrants its doing so in the best interests of the child" (Friederwitzer v Friederwitzer, 55 N.Y.2d 89, 96). "Since any custody determination depends to a very great extent upon the hearing court's assessment of the credibility of the witnesses and of the character, temperament, and sincerity of the parties" (Alanna M. v Duncan M., 204 A.D.2d 409; see, Matter of Irene O., 38 N.Y.2d 776), its findings "are generally accorded great respect * * * and will not be disturbed unless they lack a sound and substantial basis in the record" (Kuncman v Kuncman, 188 A.D.2d 517). Moreover, the parties' own agreement as to who should have custody of children constitutes a "weighty factor", to which priority should be accorded absent extraordinary circumstances (see, Eschbach v Eschbach, 56 N.Y.2d 167, 171).
In this case, the father had been the custodial parent pursuant to an agreement between the parties executed prior to the mother's petition for custody. The hearing court awarded sole custody of the parties' two minor children to the father. Under the circumstances, we find no reason to disturb the hearing court's determination. Balletta, J.P., O'Brien, Thompson and Hart, JJ., concur.