From PEOPLE Magazine Click to enlarge
On July 14, when Bristol Palin and Levi Johnston went public with news of their second engagement, the bride-to-be reveled in congratulations all day, even as she put in her regular nine hours managing the office of an Anchorage dermatologist. But her bridal buzz died when she got home to Johnston and their 19-month-old son Tripp that night. "Levi was just like, 'Bristol, there is a possibility I could be the father of this other baby,'" Palin tells PEOPLE. "I was bawling my eyes out, but there was no comforting from him. He's like, 'Yeah, that sucks; I'm sorry,' and just leaves."

Now it's Palin's turn to go. "It's over. I broke up with him," Palin, 19, says through tears. "The fantasy I had of us three being a family was all a game to him. He's never going to change."

We've been here before, but this time there's no going back, says Palin. The last straw was not the possible half-sibling for Tripp-Johnston's paternity has since been publicly denied by a pregnant former girlfriend-but learning that Johnston, 20, filmed a music video parodying his contentious relationship with her mom, Sarah, the former Alaska governor. "He was mocking my family on video," says Palin. Even after she dumped him, she says, Johnston texted, "Do you want to do a Reality show with me?" "He's just obsessed with the limelight, and I got played," Palin added. Johnston could not be reached for comment at press time.

Palin credits her mom with standing by her for the past three weeks, with "no I-told-you-so's." And when Palin decided to vacate the townhouse she bought only last February, both of her parents were at her door at 8 a.m. to load the rented U-Haul truck. "Everyone with adult children knows exactly how Todd and I feel," Sarah Palin now says. "You have to give these young adults their wings, room to make their own decisions and to learn from their mistakes." As for Bristol, she says, "Tripp and I are starting fresh."