Inside Pussycat

Inside Pussycat (1977) is a film rated 9.0/10.

a smug grad student is working on his doctoral thesis to "prove" that everyone has a schizophrenic dual nature: what one thinks one is and one's true personality. He uses drugs on three coeds to bring out their hidden natures, and has surreptitiously filmed them having uninhibited sex to prove his point.