have (got) someone by the short and curlies
US /hæv ɡɑt ˈsʌm.wʌn baɪ ðə ʃɔrt ænd ˈkɜr.liz/
UK /hæv ɡɑt ˈsʌm.wʌn baɪ ðə ʃɔrt ænd ˈkɜr.liz/

1.
完全に支配する, 弱みを握る
(informal, sometimes offensive) to have complete control over someone, especially by having an advantage over them or by knowing something about them that they want to keep secret
:
•
The company had him by the short and curlies after he signed that contract.
彼がその契約に署名した後、会社は彼を完全に支配していた。
•
She knew his secret, so she had him by the short and curlies.
彼女は彼の秘密を知っていたので、彼を完全に支配していた。