"It was a bit much for him," the friend tells OK! "There was a lot of drama - it was too much of a whirlwind. It wasn't one thing in particular.

"He likes her. They had a good time together. He was doing his best to help her out - but there is only so much one person can do."

What's next for Isaac? "Hanging out with the guys and riding his dirt bike," says the friend.

"He's focusing on his career - working and going out on castings."'

"They are no longer an item," Brandi Lord, Isaac's agent at L.A. Models, tells OK!

Meanwhile, Britney Spears could use some fashion tips reports Page Six. The pop tart was spotted in the bathroom of the Carlyle Hotel on Friday about 11 p.m., primping with friends in front of the mirror. Our spy overheard Spears complain, "Y'all, I feel old! I'm 24, y'all. I feel old." She was wearing "a red tank minidress, no bra, and huge platform shoes" and had "nappy hair extensions." Spears asked the spys, "What should we do in New York? This place [the Carlyle] feels old."

In other news, TMZ spies caught Britney Spears enjoying a night of drinking and partying with former *NSYNCer JC Chasez at club Marquee in NYC, when Spears had a very public jealous moment.

With her black thong underwear sticking out of her jeans, Spears decided to check out the DJ booth. Just as she got over to the wheels of steel, the DJ pressed play on a Justin Timberlake track.

According to a Spy, Britney exchanged a few words with the DJ, and the Timberlake track was promptly replaced with something more to her liking.