I think i have a stomach fetish, iin?

Whenever I'm in bed with my girlfriend I like to put my hand up her top and just kinda, either rub or put my hand on her stomach\lower chest (I've done it to previous girlfriends too).
Something else her and I do is I rub my penis on her stomach until I eventually climax over it, I really love it and she's told me she really likes it too and turns her on, is this weird to enjoy doing this?
(I only want to do it to girls though, not myself or other guys.)