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

1.
menguasai seseorang sepenuhnya, memegang kendali penuh atas seseorang
(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.
Jaksa benar-benar menguasainya dengan semua bukti.
•
If you owe them money, they'll have you by the balls.
Jika kamu berutang uang kepada mereka, mereka akan menguasaimu.