a word in (one's) ear
A private, often brief, communication with one, often to issue a suggestion or warning. I'm confident that that intern will stop slacking off once I have a word in his ear.
a word in someone's ear
BRITISHIf you have a word in someone's ear, you speak to them quietly and privately, usually to give them advice. I really don't think he should speak to Alice like that in meetings. Perhaps I should have a word in his ear. I'll go and see Quennell. It won't be official, mind. Just a word in his ear over a drink.