Britney Spears has spent Fashion Week in New York City with her oldest son Sean Preston, and snitchs say there’s a good reason for that. The Baby One More Time singer has reportedly been canned by McDonalds’/Payless model Isaac Cohen.

I.C broke the news to Britney during a long-distance phone call Sunday evening while she was in New York and he was at home in L.A.

“They are no longer an item,” Brandi Lord, Isaac’s agent at L.A. Models confirms.

The pair enjoyed Britney’s first relationship since she pulled the plug on her marriage to another advertising man, Nationwide Insurance’s Kevin Federline.

Last month, Brit dropped $40,000-a-night on a suite at the Palms Casino Resort in Las Vegas for a romantic getaway for the pair.

Isaac is currently staying with friends and caring for Snow White, Britney’s newest teacup Chihuahua.

“It was a bit much for him,” a friend of I.C’s snitchs. “There was a lot of drama – it was too much of a whirlwind. It wasn’t one thing in particular.

“Her 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.”

But the source dishes that Isaac’s got big plans for his post Britney future: “Hanging out with the guys and riding his dirt bike. He’s focusing on his career – working and going out on castings.”