someone with a compulsive desire to expose the genitals
同义词：flasher
someone who deliberately behaves in such a way as to attract attention
同义词：show-off
英汉双解大词典
exhibitionist/ˌɛksɪˈbɪʃənɪst/(exhibitionists)
1.
N-COUNT（可数名词）
An exhibitionist is someone who tries to get people's attention all the time by behaving in a way that most people think is silly. 喜欢出风头的人[表不满]