Top definition
Flirting with or hitting on your good friend's very serious girlfriend. Named after "Koon" of youtube fame. Kooning is often made possible when the boyfriend is away and the girlfriend shows pity for the kooning boy which is misinterpretted by the desperate despicable kooner as affection. Kooning is not cheating because the girlfriend is very pleased with her current boyfriend which just makes kooning all the more despicable.
"Did you see Alex kooning last night? If Nick knew he would beat the shit out of him!"

"How can you respect anyone who koons as much as he does? Doesn't he realize he doesn't have a chance?"
by Bob321 March 17, 2007
Get the mug
Get a Kooning mug for your friend Manley.