Daily Chinese Idiom Guessing Game
Cannot help doing something; involuntarily or spontaneously.
由不得自己，控制不住自己。
清·曹雪芹《红楼梦》第八十一回我也不很记得了，但觉自己身子不由自主，倒象有什么人，拉拉扯扯，要我杀人才好。”
He couldn't help but laugh at her joke.