Nervous...this one is indeed great

A small, uncertain, and nervous witness was being cross-examined.

The lawyer thundered, "Have you ever been married?"

"Yes, sir," said the witness in a low voice. "Once."

"Whom did you marry?" the lawyer demanded.

"Well, a woman," the witness answered timidly.

The lawyer said angrily, "Of course you married a woman. Did you ever hear of anyone marrying a man?"

And the witness said meekly, "My sister did."