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 respectanyone who koons as much as he does? Doesn't he realize he doesn't have a chance?"
Kinky new fad that kids of Metro Detroit take part in during their free time and immense boredom. The actual act varies from group to group, but almost all variations of Plo Kooning involve a luffa, body wash, and an open mind.