I remember this movie where two people are having sex in the toilet, then a woman knocks out the guy and turns into the woman he was having sex with (I think?).

Furthermore, before knocking him out the woman was touching herself and the body she was assuming at the time felt the pleasure vicariously in the back of a car with a man and woman in the from

Was in English and in colour, can’t recall how long ago I saw it. Could have been a tv show but I recall it being much longer than your average episode.

Any ideas? Thanks.