Pulling a practical joke. Before Jeffrey Dahmer was a psycho serial killer, he was an alcholic class clown at his high school. Classmates reffered to any practical joke or crazy antic as "doing a Dahmer". Later, it would come to mean "killing, having sex with, and dismembering a man".

see the A&E Biography of Jeffrey Dahmer for the actual mentioning of this phrase
Joe: Kevin was just doing a Dahmer right in the middle of class
John: Oh my God! The teacher didn't stop him?!
Joe: Dude, calm down. It means played a joke.
by Amata May 23, 2008
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Cutting off a mans cock and balls, freezing them in a bag to use as a anal sex toy once frozen. Upon freezing, repeatedly sick the solid cock in your own arse whilst eating the remains of the already dismembered body.
Hey bro what did you do over the weekend??

I tried this thing called "doing a Dahmer" , it was fucking sick as. Im definitely going to do it again. If your doing nothing this coming weekend, come over and I'll explain how it all works while we have a few beers 🍻
by Ambetz November 27, 2022
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