These puns made me smile - I hope they do the same for your son!
1. Did you hear about the guy whose whole left side was cut off? He's all right now!
2. I wasn't originally going to get a brain transplant, but then I changed my mind.
3. Have you ever tried to eat a clock? It's very time consuming.
4. What's the worst thing about planning a party in space? You have to planet.
5: It was an emotional wedding. Even the cake was in tiers.
Image credit: https://en.wikipedia.org/wiki/Pun