Mr Jealousy (1997)

I thought this movie was so cute, I really enjoyed it.
I also had never thought too much of Eric Stoltz, but here I thought he was great.
My favourite parts were the scenes with him and his best friend. One of the subplots is Eric's character is going to therapy to spy on his girlfriend's ex-boyfriend, but to avoid talking about his true life, Eric pretends to be his best friend. Eric tells his best friend this, and over time his best friend expects to hear what he learned in therapy. Eventually Vince decides he wants to go to therapy too, and pretends to be Eric, but puts on a really bad English accent because he said it felt right, haha.
Most of Mr Jealousy is about Eric's obsession with the fidelity of his girlfriends. He plays it very well.
I also really like how the film is set in New York. It gave it a kind of neo-Woody Allen, self-analysis vibe, which was pretty cool.
I say this film is worth checking out.