In any event, a party wishing to annul one of those agreements seems to want the agreement to be otherwise contractually excluded. In the legal world, cohabitation collapsed on stage in 1976 with the complaint against actor Lee Marvin by the woman who had lived with him for 6 years (and had taken his name), Michelle Marvin. In this case, the question was whether Lee Michelle had made a legally binding promise to divide property and support it for the rest of her life, even after her relationship ended. In the years leading up to Marvin v. Marvin, it was generally agreed that, because cohabitation was not socially desirable, agreements between concubnats on the exchange of money or property were unenforceable; They were corrupted by the „quid pro quo” (something valuable exchanged by one party for the performance or performance promise of another party) that was assumed to be part of any cohabitation agreement: non-marital sex. However, the California Supreme Court`s Marvin opinion concluded that sexual relations were severable from a concubine`s agreement on financial matters, unless the contract explicitly depended on the exchange of sexual relations. Of course, a partner who wanted to impose such a contract had to prove its existence; However, California has decided that it will impose not only written or explicit contracts, but also oral and tacit contracts. Moreover, even in the absence of a treaty, the court was prepared to use its „just powers” to obtain justice. In other words, the court would rely on principles of fairness to achieve a fair result, even without relying on specific legislation, for example when the conduct of the parties (e.g. B provoke unfair trust or use services free of charge) justifies it. The purpose of the legal formalities is to provide spouses with codified protection against matrimonial agreements that do not result from free and informed consent.
A contract under the Matrimonial Property Act is not applicable without the legal formalities. However, compliance with formalities will not necessarily protect the agreement from attack. Nevertheless, a minority of state courts continue to refuse to impose concubine contracts and to treat concubnats as persons outside the law for various reasons. These include the continuing uncertainty about the impact of cohabitation on marriage and the desire for non-judicial legislative intervention in such an important public institution. . . .