Last year at this time, I couldn't figure out where all of Xander's undies were disappearing to. He used to have 12 pairs, and he was down to 4.
One day, Xander was in the bathroom for a while, so Blair went to check on him. He found him stark naked and standing in front of the toilet looking in. Blair asked him where his underwear went.
Xander explained he had flushed them down the toilet because they were dirty.
Case solved.
