NEKROMANTIC (1987)
Directed by Jorg Buttgereit
Only the Germans would cook up something like this—basically a porn film for necrophiles. This extremely low-budget German production does enjoy a major cult following, thanks in large part to the fact that it was promoted heavily by Film Threat Video magazine, which also just happened to release it (and its sequel) on videotape in the U.S.
A guy who works for a cleaning company that frequently mops up after gruesome fatalities takes a corpse home to his girlfriend. They have sex over the corpse, then she has solo sex with the corpse. Then she dumps her boyfriend and runs off with the corpse.
That, folks, in a nutshell is the plot of this movie, which also features the real-life killing and skinning of a rabbit.
I didn't find it satisfying, but I suppose for someone looking for something over-the-top, it's worth witnessing as a human oddity. A sequel featuring more of the same was also released.