1. Have sb. on a short leash 管得很严，牢牢控制
John's such a pen-peek; his wife always has him on a short leash.
约翰是个“妻管严”，老婆对他控制得很紧。
链接：
严格控制某人：Keep sb. on a short leash
2. Have someone's number 清楚某人的底细，看穿某人
She dare not do anything to me. I have her number.
她不敢对我怎么样的，因为我对她的底细一清二楚。
链接：
看穿某人：
see through sb.
I know your numbers.
I know your true color.
