I said ears and I'll explain. No I'm not a ferengi. The sound of your lover's breath and/or lip-smacking sounds as she's kissing your ear.... ooh god. It's like auditory overload. There's never anything else that you listen to, whose source is that close to your ears. (Well maybe headphones, but that's a fake source -- it's reproducing another sound from somewhere else.) Plus, the ear is pretty sensitive touch-wise, and it's rarely touched in the course of the day, and even if it is, it's rarely explored, all of the curves and crevices. Those are touch-nerves that never get touched, so when they are touched.... it's even more sensory overload.
Related: Does anybody else like the feeling when you clean your ears out with a Q-tip? Heheh there was a Dilbert cartoon about this once.
Dilbert: You know that feeling you get when you first stick a Q-tip into your ear?
Dogbert: Yeah.
Dilbert: Do you think that's a sin?
Dogbert. I don't know. Why?
Dilbert: I went through a whole box today.
I think it's related to what I said earlier about how those touch-nerves are never touched so they're ultra-sensitive.