Severus Snape's Severe Psychological Spanking

Severus Snape is a bad teacher. McGonagall takes notice. Severus needs to be punish- okay, wait, that sounds WAY too dirty! Okay - Snape has horrible teaching methods, and McGonagall embarrasses him verbally. There were no paddles, no pale butts, no aging hands in motion. Just talking. So... enjoy, I guess.