In the case of Marvin v. Marvin (8 Cal.3d 660, 134 Cal.Rptr. 815, 557 P.2d 106
(1976)), the famous actor Lee Marvin met a lounge singer and they started a
relationship. They lived together for 9 years, even adopting his name (even
though they never married). Lee Marvin eventually threw her out. She sued,
arguing that he promised he'd take care of her the rest of her life. He argued
that there was no written proof and it would be in contradiction of public
policy (they were not married and supportive contracts that involved sex were
not enforceable).
The California Supreme Court
decided that these contracts were
now valid.
This was the beginning of
the concept of palimony.