The situation that occurs when your dick is so far down a dude's throat that your balls gently rest on his chin. Often performed along with elbow deep ass fisting. This technique is especially pleasurable when the receiving dude hasn't shaved recently as the hairs will gently tickle your balls.
Stephen Kendrick: Dude I was face fuckin Mr. Grubb so hard last night I was ballzonchin for like 30 mins.
Everyone: You have balls?
Stephen Kendrick: Nah, I'm short and gay as fuck. I just want you guys to like me. Will you guys go ballzonchin on me?