An agreement in Family Court between a jazz singer and her former manager/fiance not to talk to each other effectively voids the estranged couple’s business contracts, a unanimous state appeals panel has ruled, affirming a lower court.

“This case, apparently one of first impression, aptly illustrates the well-known axiom that cautions against mixing business with pleasure,” said Justice Rolando Acosta, who wrote the unanimous Appellate Division, First Department, decision handed down Thursday.