I used to watch this movie as a child so only remeber one scene:
couple is in bed after sex, woman writes a promise on a balloon to always take care of the man (husband or boyfriend not sure). later they split, the man takes teh woman to court asking for a settlement or some kind of alimony because of her promise and has the old deflated balloon as proof.
sorry i was really young and dont remember any details
Sweet Revenge (1990) – http://www.imdb.com/title/tt0100725/