The feeling when you discover something odd, weird, abnormal, freaky, etc and are left with a feeling of arousal.
Guy One: Dude she is going to bone me, except the other way around.
Guy Two: Are you talking about pegging?
Guy One: What's that?
Guy Two: Instead of a man fucking a woman in the ass. She puts a strap on and she fucks him in the ass.
Guy One: Oh, lol no.
Guy Two: Well when I read "except the other way around" I thought the worst, but was slightly curoused.