Never been so up for that, mainly because it involves alcohol (and I'm not big on that) or potentially sticky drinks, which bring it all too close to the whole food-sex concept that, with the exception of one very specific food, I find totally revolting.

As to gunk in belly buttons... it doesn't take much to clean them out, and given all the little bugs living in our clothes and on our skins, the germs in a kiss, all that stuff... it's no better or worse.