When you are doing anal with a partner, and said partner has loosened up to the point where feces have begun their journey towards the rectum. Your "John Thomas" is being surrounded with anal butter essentially pickling your schlong. In other words, "Shit-Dickle'ing".
Man: Oh my god what is happening?
Woman: Honey, you're evolving!
Man: NooooOOOooooOOoooo!
Man: You're Shit-Dickle'ing me!