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When asked recently about his romance with Jessica Simpson, Tony Romo shrugged, "It's a normal relationship. There's nothing exotic or crazy about it." But the Dallas Cowboys quarterback is apparently looking for a little more excitement from his love life, because on July 9, the day before Simpson's 29th birthday, he reportedly called time on their coupling.

The New York Daily News reports the QB's decision to punt Jessica to the curb after a year-and-a-half of togetherness prompted her to cancel her planned Barbie and Ken-themed birthday party.

(In Tony's defense, he probably figured it was better to end things before he had to dress up as an anatomically incorrect doll and pretend to have a good time.)

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"Jess was too heartbroken to have a big bash," says a confidant of the popster. "She knows that she and Tony are broken up for good."

So, why did Romo pull the plug on what Simpson has called their "big-time" love?

"It's been difficult lately," an insider explained to People magazine. "He's busy with his career and she's getting ready to shoot her show ['The Price of Beauty']. They decided to part ways."

But another source says that's just a convenient excuse.

"It was a long time coming -- he hasn't really been into her and the relationship for awhile, but stayed together because he didn't want to look like a jerk for not having a better reason to break it off," a mole asserts to "And she's trying to save face by saying that it's because of their busy schedules."

One deal breaker may have been Simpson's and Romo's diverging life paths.

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"Jessica was ready to settle down, and Tony was not," a snitch tells the New York Daily News. "He travels a lot for his games, and having a full-time girlfriend is a big commitment."

It may have also been cutting into his party time. On Monday, Romo hit a Los Angeles hot spot with his buddies and pointedly ignored paparazzi questions about the bust-up. Three nights earlier, on Simpson's birthday, he supposedly gave his rusty flirting skills a workout while hanging with pals and downing Grey Goose at another L.A. club.

That's quite a change from July 1, when Jessica and Tony were all smiles at a golf tournament in Maryland, where she belted out the national anthem and he played a few holes with Tiger Woods. It turned out to be their final public appearance together.

"It wasn't an act, but they were having their problems," a source tells Life & Style of the golf photo op. "They were kind of off and on at that point."

Echoes a spy to People, "They've been having a lot of problems lately in general."

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That apparently included plenty of squabbling, an issue that purportedly plagued Simpson's relationships with John Mayer and ex-husband Nick Lachey, both of whom are coincidentally single at the moment.

"They go from one fight right into another, without a second break," a source gripes to Us magazine. "It's always something with Jessica."

But L&S assigns some of the blame to Tony, claiming, "I think he was acting like a single guy before he ever made it official."

Simpson made no secret that she hoped for a "happily ever after" with Romo, whom she began dating in November 2007 after an e-mail and phone flirtation progressed into a full-fledged first date.

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"I had butterflies that you would not imagine," she told the June 2008 issue of Glamour of her pre-date jitters. "I wanted to puke in the cup holder."

Good thing she didn't toss her cookies, because Tony went in for a kiss during the first 10 minutes of the meal. "I was taken aback by someone wanting to kiss me in public," she recalled. "Because normally people are ashamed."

Jessica wore her heart on her sleeve during the romance, regularly dedicating her love song "You're My Sunday" to Romo and schmoopily referring to him as "the love of life," "the whole package," "the calm of the storm in my life," and "everything I could dream of."

"[Jessica and Tony] were good together for a long time," a Simpson source tells People. "But I guess it wasn't meant to be."

On the plus side, her future beaus know what to expect.

"To be my man, you have to put up with a lot," Simpson said last September. "I toot under the sheets, I spend a lot of money and I can belch the ABCs."

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