An Upper East Side man recently filed a suit in Manhattan Supreme Court against his former fiancee. More than two years ago, Donald Morrish splurged on a $48,000 engagement ring for his special lady, Dianne Dinardo. The relationship subsequently disintegrated, but Dinardo had grown attached to the piece of jewelry and refused to return it. In hopes of reclaiming the 4.06-carat gold, cushion-cut diamond ring, Morrish hired a lawyer and is taking his former wife-to-be to task. His legal council has kept mum on which party ended the relationship, but either way, the case underlines a mounting need for fresh couples to work out pre-prenuptial agreements before popping any questions. After all, there’s nothing that says, “I love you” more than a legally-binding property contract.