updated 07/27/2009 AT 01:00 AM EDT
•originally published 07/27/2009 AT 01:00 AM EDT
Looks like more boys' nights out are in his future after Romo, 29, unceremoniously dumped Simpson—his girlfriend of almost two years—the night before they were set to celebrate her birthday with a Barbie-and-Ken-themed bash at her parents' Encino, Calif., home. "She is heartbroken," a source says of Simpson, who once called Romo "the love of my life" and confessed she hoped for a future—and a family—with the NFL star. "I wouldn't be dating him if I didn't!" Simpson told PEOPLE last fall. But instead of building their Malibu dream house together, Simpson—who canceled her Friday night party and later retreated to her parents' home for the rest of the weekend—found herself suddenly single. "She loves Tony," says the source. "But it's been difficult lately. They've had a lot of problems."
Perhaps some of the biggest challenges they faced were Simpson's desire to get married and Romo's reluctance to go along with the plan. "She expected [an engagement] ring for her birthday," says the Simpson source. "Sometimes in those situations, it's 'put up or shut up,' and he decided he wasn't ready." In fact some sources suggest he was only too happy to choose his game over his girl. Following a disappointing 2008 season in which fans harshly criticized him for being "soft," Romo has his football future weighing heavily on his mind. "This is crunch time," says a Romo pal, who notes that Cowboys training camp starts July 29. "I definitely think he's fully committed and focused on being the best quarterback he can be."
Diehard Cowboys fans felt that kind of drive had been lacking ever since Romo began dating Simpson in late 2007 (see box). She quickly became a fixture at his games ("His football schedule is in my schedule," she told PEOPLE) and he, in turn, was often spotted at her shows when she toured with Rascal Flatts earlier this year. Even when he couldn't make a performance, Romo offered his support. "He calls her before and after every show," a Simpson source said in February. "He wants to get all the details."
The couple also shared a fondness for hanging out, be it at her Beverly Hills home or his digs near Dallas. "We just like to lay around and talk, go to dinner, or we'll go to the movies," Simpson said last year. "We do a lot of really normal things." Romo made similar comments in the June issue of Vanity Fair, telling the magazine, "We're very similar in that we both appreciate the hometown feel to a lot of things and live our life like that."
Indeed, in the weeks before the breakup, all outward signs pointed to the couple's taking their romance to the next level. For Romo's birthday in April, Simpson splurged on a boat that the couple took for a spin on Lake Lewisville near Dallas in May. "You don't buy a dude a boat in April and let him dump you in June," Romo's friend says. And only a week before the split, Romo coyly talked about his birthday plans for Simpson ("That's a secret," he said) and described their relationship as "normal." "It's going good," Romo had told PEOPLE at a June 30 charity event. "There's nothing exotic or crazy about it. We're two people who care about each other, and it's not hard to make it work when both of you want to see each other."
Yet there were some striking differences between Simpson and Romo as well, starting with how they handled their approach to the constant spotlight on their relationship. "Tony does not talk about his dating life. He's never going to issue a statement or do a press conference about who he's dating," says a Romo pal. "Then there's Jessica, who goes on Letterman and talks about it at length."
There's also Simpson's close-knit family, who have been cited as a reason for Simpson's relationship strife with her ex-husband Nick Lachey. "It's hard for anyone who is with Jess," says a friend of Simpson's. "She doesn't have boundaries with her parents. She tells them everything. So you have two extra people in your relationship knowing everything that is going on. When you have a fight, it's not just between the two of you. Everyone is weighing in."
But it's Simpson's family who have helped her through this tough break-up. In a post on his Twitter account two days after the breakup, Simpson's father, Joe, wrote, "Love is much harder to do than say." Ashlee Simpson-Wentz also sent messages to her big sister saying "happy happy birthday may all your dreams come true!!" (As for Lachey—who recently split with his girlfriend of nearly two years, Vanessa Minnillo—a friend of his says, "Jessica is so far in his past, her personal life is basically a nonissue to him.")
To help get over her relationship, Simpson is looking forward to a new chapter in her career that includes her upcoming VH1 show The Price of Beauty, in which she will explore the extremes that women around the world go to to look flawless. She is not one to sulk. "Everyone needs to know that hope floats," she said on Twitter. "Grab the strings and pull it back to you." Does that mean Simpson is holding out for a reconciliation with the man she once thought was the One? "They could get back together again, but I doubt they will," says the Simpson source. "They both decided it was best to move on."