In Alison D. v. Virginia M. (77 NY2d 651 [1991]), two women in a committed relationship decided to have a child. They agreed that Virginia would be artificially inseminated and bear the child. For about two and one-half years after the child's birth, they both raised the child as joint custodians. The parties then terminated their relationship. However, for another two or more years, Alison continued visitation with the child. The child referred to her, as well as to Virginia, as "mommy." Virginia then terminated Alison's nearly five-year relationship with the child. Alison petitioned for visitation which was denied by the trial court. In a per curiam opinion, the Court of Appeals held that there was no statutory basis for Alison's petition. They also declined to read "de facto" parent into the definition of parent in Domestic Relations Law 70. There was no mention of any constitutional right of the child or what might be in the child's best interest. It would seem that Alison D. could have come out the other way if the principle of equitable estoppel was applied. The fact pattern is nearly identical to that in Judge Cooney's thoughtful opinion in Matter of J. C. v. C. T. (184 Misc 2d 935) which permitted nonparent visitation on an estoppel theory. Very similar is Jean Maby H. v. Joseph H. (246 AD2d 282) where the Court applied the estoppel theory to prevent a mother from cutting off visitation of the child by the child's non-genetic-father. The Court here has not relied on the estoppel theory because one of its elements, the consent of the biological parent to the formation of the child-non-parent relationship, is missing. Even so, from a child's best interest focused point of view, this consideration would drop down on the importance scale. See also Mancinelli v. Mancinelli (203 AD2d 634) where, despite an HLA test establishing nonpaternity, the Court held that the husband was estopped from denying this two-year-long "de facto" fatherhood of his child in an attempt to escape his child support obligation.