What jokes should men and women tell when they get along too dull?

One sister's signature: I'm not tall, but not every man has a chance. As soon as I saw it, I called her and said, "Do you want to add the word' Shang' to your signature?" She thought for a moment and said, "hmm." The next day I saw her signature changed to: I am not tall, but not every man has a chance to do it.