Enjoy them, soon they're going to be miserable human beans, and it's nothing you've done, it's a hormonal thing. It's not that your a bad parent, they're just going through hugh changes. Then the really cool thing happens. The get over being a teenager, and really love you again! It's so awesome. It's finally starting to happen with my youngest, but my oldest and my soldier have already passed that point. It's THE most amazing transformation you can imagine. Just when you hit rock bottom as a parent, the kids lift you back out. It's so cool!
Freind had this on his fridge - "Teenagers - move out now while you still know everything!"