Unique Costume

A man went to his boss's costume party with nothing on but a young naked woman on his back.

"So what the hell are you supposed to be?" the boss asked.

"I'm a snail." The man replied.

"What a load of crap!" his boss spat. "How can you be a snail when all you've got is that young naked woman on your back?"

"You've got it wrong," the man replied. "That's Michelle."