In real life? My gay (male) sex kink. I'm a lesbian, by the way. Het doesn't turn me on at all, and it isn't to say I don't love gay female sex because oh boy I do. Still, most of the porn I watch is gay male/slash/yaoi/etc and I like to envision myself take it up the ass by another dude, but the fantasy only works if I imagine myself being a guy, too. If I think of myself as a girl, I get turned off so fast.