the result of some dumb bitch not wiping her ass properly (back to front as opposed to front to back) and then you try going down there and there are shit crumbs in her lips and those little fuckers get in your mouth and now you've got shit breath you dirty fucker. also, rubbing your own defecate onto a girlie's privates.

when you pull your pants down and stick someones nose in your butt crack and fart on their face

Penial insertion into the Vagina, preceded by vaginal insertion. High risk of UTI and other vaginal infections. But loads of fun (sperm:-)

When one guy is eating a girl out while another guy is in behind licking her bum hole

Some one who like dirty muffins and likes to dig the dirty clam. otherwise known as dirty bearded clam.