Who's is this?

Three days a week I get up early to play basketball with about 8-10 other guys in the church gymnasium. The other morning right after we started there was a fast break and someone scored. We went back down to the other end of the gym. As we were all standing there, one of the guys who plays, holds up something black and says, "Who's is this?"

We all looked down the court to see him holding a black thong. No one claimed it. I can just see it on Sunday when the bishop gets up to the pulpit and announces, "We found this in the gym this week so if it's your please claim it."