There was an artist who worked from a studio in his home and specialized in nudes. He had been working on what he thought would be a masterpiece for several months now.
As usual, his model reported, and after exchanging the usual greetings and small talk, she began to undress for the day's work.
He told her not to bother, that he felt pretty bad with a cold he had been fighting. He told her that he would pay her for the day, but that she could just go home. He just wanted some hot tea and then, off to bed.
The model said, "Oh, please, let me fix it for you. It's the least I can do."
He agreed and told her to fix herself a cup, too. They were sitting in the living room just exchanging small talk and enjoying their tea, when he heard the front door open and close, then some familiar footsteps.
"Oh my God!" he whispered. "It's my wife! Quick - Take your clothes off!"