Justin Bieber and Selena Gomez NOT Back Together? 'Believe' Crooner Flirts with Older Blonde Beauties in NYC after Celebrating Ex Girlfriend's Birthday with Sexy PDA

"Come & Get It" songstress Selena Gomez just celebrated her 21st birthday on July 22. Apparently, Justin Bieber showed up for the celebration with a single red rose... sources claim that the former couple partied together all night (with some hot-and-steamy PDA). Of course, this rekindled rumors that Jelena was officially back together! But apparently not... Bieber's still playing the field! On Monday evening (July 29), the "Believe" crooner and his crew hit up NYC's popular Catch restaurant. The Biebs was spotted flirting with a group of older blonde beauties... and even asked for one pretty lady's number! What's up with that, Selena?

The 19-year-old pop star partied with his pals earlier this week in NYC:

justinbieber: "The crew and Chaz open ur eyes for once."

JB's manager Scooter Braun was also there.

And apparently the Biebs was having a blast... with some lovely (older) women:

"Justin was surrounded by blondes," a gorgeous partier told HollywoodLife.com. "He flirted with me all night. He was tweeting up a storm while he was there and he even posted a smiley face and showed it to me. Then he asked me for my number but I didn't know what his situation was with Selena and he's several years younger than me, so I didn't... He was really surprised when I said no and he said, 'don't you want to hang out at the after party?' But it was already 2 a.m.! I just looked at him and said no, laughed and then left with my friends. He seemed totally sober but he was flirting with girls all night. He definitely seemed single."

Bieber and Gomez never came out as a reunited couple following the "Spring Breaker" beauty'd b-day bash... so maybe they're just having some fun, no strings attached?