I'm not sure if we covered this one before.
A man and woman were having dinner at an exclusive restaurant. Their waitress was taking orders at an adjoining table when she noticed the man was beginning to slide off his chair and onto the floor beneath the table.
The waitress observed it until the man had slipped completely beneath the table, but still the woman continued to eat without any notice of the disappearance.
When the waitress completed taking the order, she approached the table and said, "Mam, pardon me. But I think your husband has slid under the table!"
Not missing a spoonful of desert, she replied, "Oh, no, he didn't. He just walked in the door."