not someone's keeper

not (someone's) keeper

A rude or flippant way to say that one is not be responsible for another person's actions, behavior, or whereabouts. Of course I'm disappointed that Travis got arrested again, but I'm not his keeper. How should I know where Mary is? I'm not her keeper.
See also: keeper, not

not someone's keeper

If you are asked where someone is and you answer that you are not their keeper, you are saying in quite a rude way that you do not know where they are and you cannot be expected to know. `I've no idea where he is,' Hughes replied, `I'm not his keeper.'
See also: keeper, not