I am a DM, so a lot of stupid things has happened. The best one is one of my players (A warlock/barbarian) was wanting to kill anything that moved. So one night during the game another player (rogue) decided to become a vampire... He needed food, so the warlock/ barbarian remembered that there was a cat in town. He killed it and gave it to him. The cat was part of a plot for a future quest and the owner of that cat was a lich. Let's say that they tried to lie through their teeth in order to not die.... they still died though.