Poison Ivy spotted a very intoxicated Justin Timberlake at Avenue lounge in New York's Chelsea district Monday night, kissing, holding hands and canoodling with an unknown brunette in a white hat (see above).
Only problem is, JT is still publicly together with Jessica Biel!
Why would you cheat, JT?
In a crowded club, of all places???
Timberlake was so limber off Patron shots that he started dancing alone atop his booth (see top photo). He also treated guests (including Lindsay Lohan and Owen Wilson) to a three-minute breakdance in which he rolled around the floor and accidentally crashed into surrounding patrons.
Lohan, just a few feet from the scene, Tweeted when she saw JT with the brunette around three a.m.: "...where's jb [Jessica Biel] cheater?" she wrote.