Anyone from or have lived in, Germany? I have an exchange student here & I'd like to tell him a joke in German that he will find funny.

He is only visiting for a few days (host family is our extended family who are visiting us & leaving soon) & I have noticed that the jokes & humor that we enjoy, doesn’t really translate well. So if anyone out there is from Germany & knows a funny 1 or 2 liner joke in German, that would be considered funny in Germany, I would love to know it. He is about 17 years old. Doesn’t need to be a dirty joke, just a joke that he would laugh at, even if it’s a dumb joke, just something he would enjoy. I would really like to make him laugh & feel a little at home. Thank you so much for anyone who can help. Again, I only have a couple days, so time is of the essence. :)