Bristol Palin exclusively tells the new Us Weekly that her mother Sarah Palin "doesn't really approve" of her surprise engagement to Levi Johnston.
"She's apprehensive and concerned about this. She doesn't want to see me get hurt again," says Bristol, 19, who first broke the news to Us Weekly that her ex Levi, 19 -- father of 18-month-old son Tripp -- popped the question about a month ago.
PHOTOS: Bristol and Levi's relationship: A look back
Sarah has made no secret of her feelings toward Levi, 20, who infuriated her last fall when he claimed that she had called her infant son Trig (who has Down syndrome) "retarded." She sniped back that anyone who would pose for Playgirl would "say and do anything for even more attention." Later, during an interview with Oprah Winfrey, she dubbed him "Ricky Hollywood" and called his "aspiring porn" career "heartbreaking."
Indeed, tensions remained high after Us Weekly broke the story, when the Palins released a tense statement: "Bristol believes in redemption and forgiveness to a degree most of us struggle to put in practice in our daily lives."
PHOTOS: On again! Stars who rekindled a romance with an ex
Admits Bristol in the new issue, "My mom is not 100 percent backing us up right now."
How did Bristol break the news to Sarah? Over the phone -- after she gave an interview and did a photo shoot in Us Weekly.
"She knew Levi and I had been talking, but she wanted to know if Levi was really sincere about this," says Bristol. "I told her we were working on our relationship for Tripp, and she told me, 'Actions speak louder than words.' She's going to wait to see if he changes... But she's just glad he is getting on the right path. She knows how much Tripp means to me, and she wants Tripp to have a father figure."
Since becoming engaged to Johnston again (the two called off their first engagement just two weeks after welcoming their son in December 2008), "What I've done is starting to sink in, and every family member of mine has some concerns -- and that is scaring me. My dad is on the same page as my mom: they don't want to see me get hurt. They don't want to see again what I already went through with Levi."
PHOTOS: Who will say "I Do" next?
"People are more worried for me than excited for me," she tells Us.
For more details -- including if Sarah will attend their wedding, what Levi plans to do to prove himself to the Palins and who Bristol refuses to invite to her nuptials -- pick up the new Us Weekly, on stands today!