One of the funniest things I remember actually happened after a session. We had done electrical play and the sub's whole area down below was a bit numb at the end. He left the session and went to his favorite watering hole for a drink. While sitting there he reminisced about the session and had a spontaneous orgasm in his pants. He then proceeded to get totally pissed (drunk) because he couldn't leave until the front of his pants dried.