If someone keeps telling you jokes, but his jokes are really not funny at all. So what should we do?

If I were you, I would only pretend to smile. I usually like to laugh, so pretending to laugh is also very similar (ahem, digression).

Out of courtesy ... and then politely ask, "shall we talk about something else?"

This not only saves each other's face, but also saves friendship.

I once told someone a joke, and she said it wasn't funny. I was very sad, so believe me, that's right!