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?"