David Wayne, the Jolly Blogger posted this observation in his excellent blog on kissing (Fridays Are for Kissing).
"Baptists are not allowed to kiss - it could lead to the consumption of alcohol."
Actually, I've always heard it the way Mark Olson put it ... with a slight paraphrase of my own to sanitize it for my younger and more puritanical readers:
Baptists don't kissing standing up because people will think they are dancing.
Definitely read Mark's comment though and all of them ... and the whole article.