be in with (someone)

1. To be in close association with someone or some group. I'm worried about Johnny—I think he's in with a dangerous group of people. I wish I were in with my brother's friends—they're all so cool! Please, a dork like me isn't in with the popular girls. They only talk to me when they want to borrow my notes.

2. To have a friendly relationship with a powerful or important person and, usually, benefit from it in some way. Now that I'm in with the CEO, I'm sure I can get you a job at our company. The superintendent is a powerful woman in the school district, so I hope you're in with her. A: "You're not in with Mrs. Melvin these days?" B: "No, not since my dog destroyed her garden."

in with, be

1. Be in league or association with, as in She was in with the wrong crowd. It is also put as keep in with, meaning "to remain in league or association with," as in He really kept in with his high school friends even while he was in college. [Late 1600s]

2. See in good with.

The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

be/keep (well) ˈin with somebody

(informal) be friendly with somebody, not because you like them, but because they may be useful to you: If you want to do well in this company, keep well in with the boss.