keep your nose clean
保持良好的行为；避免麻烦
口语·劝诫避免麻烦
英文释义
to stay out of trouble; to avoid doing anything wrong or illegal
例句
After his last arrest, he's trying to keep his nose clean and stay out of trouble.
典故来源
源自20世纪初美国俚语，鼻子干净象征不沾染毒品或违法行为，引申为行为端正。