Tony Romo broke up with Jessica Simpson on Thursday, the night before her 29th birthday, a source close to the pop star told PEOPLE.
"She is heartbroken," says the source. "She loves Tony. But it's been difficult lately. .. They decided to part ways."
The Dallas Cowboys quarterback fueled breakup rumors when he showed up with friends at the Hollywood hotspot MyHouse on Friday night without Simpson.
"He had quite a few girls stop by his dance floor table," said an witness. "Romo was sipping Grey Goose and having a fun time with the boys."
Simpson’s rep had no comment. Romo's rep could not be reached.