Kathy Griffin must be heartbroken.
"We got engaged two weeks ago," Bristol, 19, says in the article. "It felt right, even though we don't have the approval of our parents."
The couple, who appears on the cover of the magazine with their 18-month-old son Tripp, called off their engagement two weeks after the baby's birth in December 2008. They rekindled their romance three months ago while working out a custody plan, reports Us.
"I really thought we were over," Johnston, 20, says. "So when I went, I had no hope. I think we both just started talking — and then we took Tripp for a walk."
"When he left that night, we didn't hug or kiss, but I was thinking how different it was. He texted me: 'I miss you. I love you. I want to be with you again' ... I was in shock," Bristol says.
Bristol also wonders how her mother will take the news. "It is intimidating and scary just to think about what her reaction is going to be. Hopefully she will jump on board," Bristol says.
Sarah Palin has since released a statement to NBC News: "Bristol at 19 is now a young adult. We obviously want what's best for our children. Bristol believes in redemption and forgiveness to a degree most of us struggle to put in practice in our daily lives."
Calls and emails to Sarah Palin and Johnston's reps were not immediately returned.