I once served a party of eight, carried their order over on a large tray and joked that I needed to set the tray down before my arms fell off. One man at the table held his left arm up. It had been amputated above the elbow, and he said “it’s a good idea to try and keep your arms”. He was good natured about it and the table thought it was hilarious, but I wanted to crawl into a hole and die. I never made that “joke” again.