Eating Raoul (1982)

When Paul enters his apartment to find Mary fighting off a swinger who has gotten into the wrong apartment (and who thinks that Mary is just playing hard to get), he hits the man with a frying pan, killing him. Their dreams of running a small restaurant seem to be in jeopardy until they decide to dispose of the body, keep the wallet, and advertise for other sexually oriented visitors who are summarily killed, bagged, robbed and disposed of. This goes along quite well until one night a burglar named Raoul breaks in and cuts himself in for a piece of the action.