By Melissa Hunter
A source tells People, "She is heartbroken. 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."
The rumor mill started spinning Friday night when Romo was spotted at the celeb-riddled Hollywood hot spot MyHouse with 14 of his friends ... and no birthday girl.
An eyewitness says, "He had quite a few girls stop by his dance floor table. Romo was sipping Grey Goose and having a fun time with the boys."
Simpson had originally planned to throw a Ken and Barbie-themed party for her birthday, but it fell through. A solely Barbie-themed party without a Ken doll would have just been sad, really.
While reps for Romo and Simpson didn't comment on the situation, Simpson made some break-up implications in her latest tweets. Gotta love celebrities sharing all on Twitter (her PR rep probably doesn't share our love). She said, "Everyone needs to know that hope floats ... grab the strings and pull it back to you." And then a few hours later she tweeted, "Falling asleep with my mom and dogs. Please lord give all of my beautiful fans, friends, enemies, and family rest. Bring all of us peace."
Incidentally, it's interesting timing that Simpson and Nick Lachey are both single again. Might this mean a reunion? At least for a "Newlyweds Special: Rebounding with Exes." How 'bout it, guys?