Wife and girlfriend
The other day I came home from work and my wife was sitting on the couch with my girlfriend.
Stunned, I asked, "What's going on here?"
My wife replied, "You tell me."
I told her, "It looks like you're sitting here with some total stranger."
My girlfriend stood up and said, "Stranger? We've been sleeping together for months!"
I turned to my wife and asked, "My God, is this true?"