In May, 1966 the plaintiff herein obtained a judgment of separation which contained provisions for support. In the following month the parties were divorced pursuant to a Mexican decree entered upon the appearance of both parties. The Mexican decree does not mention the judgment in the separation action, nor does it make any provision for alimony or support of the parties’ children. Nevertheless, defendant continued for some six years to provide support in accordance with the terms of the separation decree. In June, 1971 plaintiff moved to amend the decree of separation to obtain increased support. No mention was made in the moving or opposing papers of the divorce. The matter was referred to a Special Referee. "While the matter was pending before the Referee plaintiff moved for a temporary increase in support. In opposing this application defendant, for the first time, revealed the existence of the divorce, but did not move to dismiss the proceeding. This last motion twas denied.
*424Thereafter, in June, 1972, the Special Referee filed his report, recommending -an increase in the amount of support. A motion was made to confirm the award and the defendant urged the court to vacate the prior order. The court confirmed the report.
Thereafter the plaintiff moved further to increase the award. Defendant cross-moved to -dismiss the proceedings. The motion was granted to a limited extent and the cross motion was denied. It is axiomatic that the divorce decree superseded the separation decree and the latter was no longer viable (Math v. Math, 39 A D 2d 583, affd. 31 N Y 2d 693; Lynn v. Lynn, 302 N. Y. 193). However, a defendant may be estopped to assert the existence of a decree, and, a fortiori, rely on it. Here there has been no proof of any facts which would justify an estoppel. Quiteiclearly defendant’s voluntary payments do not constitute such proof (Lynn v. Lynn, supra, p. 205).
"While at first blush it might appear that modification of an unenforceable -decree is an unseemly vehicle for relief, this is not the case. If the fact which renders the separation decree defunct is not asserted (as was originally the situation here), or is prevented by law from being asserted, the matter may proceed as if it were not the fact at all (cf. Psaroudis v. Psaroudis, 27 N Y 2d 527).
As indicated, partly through the deficiency of the defendant himself, the issue of whether the defendant should be estopped from asserting the Mexican decree has never been litigated. Until it has, plaintiff’s right to relief is not established. The order appealed from should therefore be reversed and the matter remanded for further proceedings in -accord with this opinion.
The order entered September 26, 1973, New York County (Frank, J.) should be reversed on the law and the application remanded to Special Term for further proceedings in accord with this opinion.