Just played a session where there was a mirror with a symbol of a full moon, as well as a nearby moondial that shows the current phase of the moon. The party deduced that the moon needed to be a full moon to work, but no one wanted to wait days until the moon was in the right phase. One of the players decided to expose their whole ass to the mirror to see if that type of “full moon” would do anything. When that didn’t work, a sorcerer in the party used an illusion spell to make the actual moon in the sky resemble the other character’s bare ass. Sadly, that also didn’t work.