near the knuckle
US /nɪr ðə ˈnʌkəl/
UK /nɪr ðə ˈnʌkəl/

1.
선을 넘는, 외설적인, 무례한
almost offensive or rude, especially because of being sexual or involving rude humor
:
•
His jokes were a bit near the knuckle for the family gathering.
그의 농담은 가족 모임에는 좀 선을 넘는 것이었다.
•
The comedian's routine was quite near the knuckle, but the audience loved it.
그 코미디언의 공연은 꽤 선을 넘는 것이었지만, 관객들은 좋아했다.