Levi Johnston is admitting that his one regret in life isn't his infamous Playgirl shoot ... but the apology he made to his baby's grandma, Sarah Palin. In that July apology, he had mentioned saying "things about the Palins that were not completely true." He's now taking that apology back!

Johnston, 20, tells the CBS Early Show:

    "I don't really regret anything. But the only thing I wish I wouldn't have done is to put out that apology [to Palin and the Palin family]. Cause it kind of makes me sound like a liar. And I've never lied about anything. So that's probably the only thing. The rest of the stuff I can live with."

As for why he made the apology to Palin in the first place, he adds, "That was something I did to make my fiancee happy."

Johnston and his now ex-fiancee Bristol Palin, 19, are the parents of 20-month-old son, Tripp. Just last month, he and Bristol ended their second engagement.

Levi also touched upon his upcoming reality show in which he's running for mayor of Wasilla, Alaska. He tells the Early Show, "If we do win, I'm going to have to give up Hollywood for three years."