It turns out men have almost as much sensitivity in their nipples as women do. Some men will tickle a nipple with one hand while masturbating with the other. This greatly enhances the arousal. There are also men who like very intense squeezing, twisting and biting of their nipples. Nipple ‘torture’ is less appreciated by most women. Nipple piercings can enhance the pleasure because simply wearing a shirt can keep the pierced person in ongoing arousal, at least while the piercing is new. Some men, and some women, can have orgasms just from nipple play.