LOS ANGELES -- People magazine is reporting that Dallas Cowboys quarterback Tony Romo has split up with girlfriend Jessica Simpson.

The magazine reported in its online edition on Monday that Tony Romo broke up with Jessica Simpson on Thursday -- the night before her 29th birthday.

"She is heartbroken," a source told People magazine. "She loves Tony. But it's been difficult lately. He's busy with his career and she's getting ready to shoot her show (The Price of Beauty). They decided to part ways."

People magazine reported that the Dallas Cowboys quarterback fueled breakup rumors when he showed up with about 14 friends at the Hollywood hotspot MyHouse on Friday night without Simpson.

"He had quite a few girls stop by his dance floor table," an onlooker told People. "Romo was sipping Grey Goose and having a fun time with the boys."

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