she knows you're not a creep. but going and making it like a "confession" will put a weird spin on it. but you don't need to tell her that you have a fetish, she'll figure it out

someone with hair that long is only going to end up with people who like long hair, and i'm sure you get to give hers attention, so it's no secret to her that you like it.

just slowly introduce things you want her to do in the bedroom, and go with what she's comfortable with.