Movie with face replacement? Not Face/Off (1997)! but maybe similar
 

There is a scene in the movie where a guy makes out with his wife on the staircase of their house, talking to her in a sleazy manner. She's turned off by it, and says something like "it isn't like you". I think the guy is pretending to be her husband. Maybe he had a surgery to make his face look like her husband's face. I initially thought the it was from the movie Face/Off (1997) with Nicolas Cage and John Travolta, but I just watched it, and turns out it isn't the one I was looking for.

I may be wrong though, and the guy is actually the real husband, and it's just that his personality changes suddenly and radically.

Any idea what movie is that?

Is it "Bruiser"?

Nope.

Might be the Tobe Hooper episode of Body Bags. Just thrwoin it out there seein what sticks

Not that one either, but thanks for your tries.

Instinct to kill

Re: Movie with face replacement? Not Face/Off (1997)! but maybe simila
 

Terminator ?

Not these ones either.

Again, I'm not sure there actually was a face replacement in the movie, I only sure about that staircase scene.

Doubt it is but could it possibly be Dead Ringers? It's about two identical brothers and there's a scene with a staircase where one of them tries to initiate a threesome and the other walks away. Not exactly what you said but kinda similar and since details get mixed up there's a slight chance it could be.

Also a big thing earlier in the film is that they are having sex with the same woman and she doesn't know but she can tell they are different, even thinking the one person she thinks it is has schizophrenia.

Re: Movie with face replacement? Not Face/Off (1997)! but maybe simila
 

It is Instinct to kill. Download and watch the movie, you will understand.

Nope.

I've watched the trailer, I'm positive it isn't the one I'm after.