^ Precisely. Sexual orientation is about WHO YOU ARE ATTRACTED TO, NOT THE ACT. The ass and the prostate are erogenous zones for most men, so deriving pleasure from having that region played with is normal. At any rate, you could like a massive butt plug up there, you could even like it if your lady fists you and fucks you with a strap on, if you like it when a GIRL does that and don't think about guys fucking you or get turned on by thinking about guys fucking you, you sound pretty damn straight to me.