have someone by the balls
US /hæv ˈsʌmˌwʌn baɪ ðə bɔlz/
UK /hæv ˈsʌmˌwʌn baɪ ðə bɔlz/

1.
ter alguém nas mãos, ter alguém sob controle
(vulgar slang) to have complete control over someone, especially by having information that could harm them
:
•
The prosecutor really had him by the balls with all the evidence.
O promotor realmente o tinha nas mãos com todas as evidências.
•
If you owe them money, they'll have you by the balls.
Se você lhes deve dinheiro, eles o terão nas mãos.