have someone on a string

have (someone) on a string

To have great influence over someone. If you want to have someone on a string, flattery always helps.See also: have, on, string

have someone on a string

or

keep someone on a string

If someone has you on a string or keeps you on a string, they can make you do whatever they want, because they control you completely. It's so unfair — she keeps him on a string and he's crazy about her.See also: have, on, someone, string