Aaron Carter's Big Mistake.

Aaron Carter told Ryan Seacrest what I figured would take him a few weeks of marriage to figure out.

"I made a mistake and she did too. We both did."

Carter proposed last week to his girlfriend, Playmate Kari Ann Peniche in Las Vegas. Here's a detail I hadn't known: he'd only known her for five days, and she was an ex-girlfriend of his older brother, Nick. A full interview is airing on E! tonight.