I saw this in high school (89/90) and can only remember one of the final scenes. The guy gets with this girl in the back of a van. I think he was supposed to be a Vietnam vet? He finishes on her and it's a pretty facial scene at first but then he keeps going and going. It becomes a comically large load on her and there are sounds of bombs and machine guns going off as he's spraying her. It's a long scene and she's drowning in the stuff at the end. When he's finished one of them says "Want to go again?" I have a vague memory of a girl earlier in the movie that may have tried to mount an oil derrick pump.

The movie was silly fun. I don't know who was in it either. Hopefully someone knows this one. Thanks