My four year old, who has been potty trained for a long long time, just pee'd in his pants.
Whats annoying is as my wife's pregnancy progresses, and his behavior becomes worse, we joked last night that at least he hadn't reverted to going in his pants.
Guess again. The wife told him that going potty in his pants is the one thing about little baby's that we really don't like. He seemed to understand.