Bung hit is when you pass gas in such a manner and circumstance that the victim must breath the fumes or suffocate themselves.
Skip gave Buffy a Bung Hit in a Dutch-Oven. Then Buffy moved out.
A bung-hit is when person A (receiver) seals their lips around persons B's (giver) anus. Then person A passes gas and person B inhales deeply and holds their breath.
Offering, or suggesting, that someone receive a bung-hit is considered to be a vulgar insult to many; and therein lies its value in communication.
In a sarcastic and obnoxious tone:
"Hey, why don't you plant your lips around my anus and I will fart and you inhale deeply. Have you ever had a bung-hit before?"