The act of soaking a tampon with alcohol and ingesting it through one's anus.
Andrew: Sweet! A tampon!
John: I'll grab the liquor. Let's butt huff!
To forcibly cough into ones anus.
That ho was owning my asshole with an awesome rim job, when she started coughing into my ass, she had aids and was about ready to die from a simple cold, and she told me that wasa butt-huff.