Been awhile since I did a rock star one. This now married B+ rock star and father with A+ name recognition had a very weird crab obsession. No, not the eating kind. Seems that whenever he went on the road and decided to have some groupie sex, the women he decided to be with had to be completely shaved because he was paranoid about crabs. If she wasn't, she had to right then. Seems he had been the recipient of the infestation not once, but twice and had to do some explaining when he got home from the road.
Rod Stewart (To be clear, this was back in the day, well before he married Penny)