be in on

1. see in on.

2. Also, get in on. Be or become a participant; be or become one of a group who have information. For example, Is she in on our secret? or I'd like to get in on this venture. [c. 1920] Also see barge in on; ground floor (get in on the); in good with.

Example Sentences

Even bridal wear can be in on the act, with pregnancies “showcased even as women walk down the aisle.”

From Slate

It was all about youth, attention, and a willingness to be in on the joke, even when we were the punch line.”

From Slate

“She’d be in on anything if she thought it was a game to be won in anything it was about, whether it was H.O.R.S.E, whether it was an actual game, whether it was cards — she wanted to win,” Walker recalled.

From Los Angeles Times

Its theatrical release will be in on Thanksgiving Day 2026 and premiere on Netflix on Christmas.

From Los Angeles Times

We can all be in on the joke, and sometimes the joke is sex.

From Salon