LOL! Actually, the worst thing I've ever had one of the kids do was cutting up a comforter set I had just bought. My son was fascinated with scissors and one day I caught him cutting up the dust ruffle. He was about 3 years old at the time. Needless to say, I was plenty peeved.
Yeah, it's pretty hard to get too mad at a 3yr old. That's why kids are born so cute, so their parents won't murder them before they reach adulthood. ;o)