Equitable estoppel “is imposed by law in the interest of fairness to prevent the enforcement of rights which would work fraud or injustice upon the person against whom enforcement is sought and who, in justifiable reliance upon the opposing party’s words or conduct, has been misled into acting upon the belief that such enforcement would not be sought.” Nassau Trust Co. v. Montrose Concrete Prods. Corp., 56 N.Y.2d 175, 184, (1982), rearg denied 57 N.Y.2d 674 (1982); Readoco, Inc. v. Marine Midland Bank, 81 F.3d 295, 301 (2d Cir. 1996).