There's an episode of Friends where Ross has a fancypants award ceremony to go to. At the end, Rachel tells him she's going commando. And Ross gets all pant-y (pardon the pun). I asked Archie, "Is that hot? Do guys really like to be told by their partners when they're not wearing underwear?" Archie assured me that this was, indeed, very sexy. "But why? Is it because you'll sneak away to the restroom and have sex at the oh-so-chi-chi restaurant? Why?" "Because it's the idea that the woman is all naked down there. It's like the promise of sex. You wouldn't have sex on the table between the salad and soup courses -- but you could. Because there wouldn't be any underwear."
I think that's just stupid. I mean, there's no way to persuade someone that something they find sexy or arousing just isn't, but I think it's kind of lame. And since I prefer to wear undies, I've found a solution that cracks me up.
I whisper, "Honey. I am completely naked underneath my clothing!" Oddly, Archie doesn't find this hot or particularly funny. But it cracks me up every single time.