In Chopin v. Chopin [Chopin v Chopin Arizona Div 1], as part of their divorce in February 2007, Husband and Wife entered into a spousal maintenance agreement that stated, among other things, that spousal maintenance would terminate "upon Wife's remarriage or romantic cohabitation" with another. The term "romantic cohabitation" was defined in the spousal maintenance agreement as including a financial support requirement and means "living together and behaving as a married couple", rather than merely a "romantic relationship".
When drafting divorce settlement agreements, perhaps a reference to Chopin would wise to further clarify the intent of the parties.