Some friends and I were on the way to Vegas. We had a few drinks and I guess hit the limit they serve on a flight. We had been having a conversation with a guy next to us about small talk things, joking, wharever. This guy then looks at the stewardess and says “they’re fine, and there is no need to cut them off”. She then kept bringing drinks until we landed. At that point we started joking he was an air marshall, and he laughed it off.
Once we got in the terminal he kinda flashed his ankle holster and told us to have fun on our vacation. Also mentioned something along the lines that we had made a normally boring 5 hour flight entertaining.
I should add this was 10+ years ago.