A California court has decided that a former husband must continue paying his ex-wife spousal support, although she has registered a domestic partnership with the state. The court found domestic partnership to be equivalent to cohabitation, rather than marriage.
State marriage laws end spousal support when the person receiving it dies or remarries, unless otherwise specified in an agreement. Although the ex-husband supports same-sex marriage and knew the ex-wife was living with another woman, he claimed he would not have signed the spousal support agreement had she disclosed that she had become a domestic spouse a few months earlier.
Source:
http://www.latimes.com/la-me-gaywed22jul22,0,315735.story?coll=la-home-center

