2. Having sex with someone named Alan.
3. To deal unto others violence in the most unpleasant manner imaginable.
Jill- "What is his problem?"
Bill- "He's just doing an Alan."
2. Bob- "So, if you're not busy later, maybe we can hook up?"
Jane- "Sorry, I'll be doing an Alan."
3. "Oh, My God! What is that man doing?"
"Just Run! He's doing an Alan."