It's clear to me that Julie Delpy's character, Marion, is very ENFP, as she played in Before Sunrise/Sunset also.
However, I can't quite pin Jack, Adam Goldberg's character. I want to say INTJ for most of the movie, with his sarcastic humor, general ability to shrug things off, viewing all the emotional & random French people as preposterous, and tendency to seek solitude. However, his sudden emotional burst at the end and occupation as an interior designer says NF male. He doesn't seem that sensitive overall though, and I don't really see Fe or Ne.
Shaving her initial into his chest hair seems like some kind of weird Ni symbolism, and maybe his emotion at the end is the tertiary Fi bubbling up.The entire dynamic of their relationship seems ENFP-INTJ.
What do you think?