I cry every time I watch La Bamba, but I'm not gay for Richie Valenz.
If its a good story, with emotional impact, especially if the music is cued perfectly, the director of that film knows they are going to provoke emotional outpouring from their audience.
I cry quite a lot at all kinds of things. If I see cute little birds it makes me so happy that I cry sometimes. If almost anything is happening on screen where its intense and super sad and/or traumatic, I get some tears. I just watched something with my wife I wish I could remember what it was, but it was something I didn't think would be so sad and it was and I cried for several minutes, very watery eyes.
but I'm a guy who is not afraid or scared to express any kind of emotion, whatever it is.
I think your friend, OP, is just very in touch with his emotions and willingness to express them easily. It has nothing to do with being straight or gay. Crying is natural and healthy for HUMAN BEINGS and I'm sure there are plenty of men today who believe, wholeheartedly, that crying is for pussies and girls and girly-men and "not real men" and their uber-masculine fantasies of what society should be like prevents them from being a fully realized, emotion-expelling human being.