mix up with else Go to mistake for
mix (one) up with (someone)
1. To confuse or mistake one person for another. I always mix Kelly up with her younger sister—they look so much alike! Sorry, I think I'm mixing him up with someone from the accounting team.
2. To involve or embroil one with some other person, especially someone who is problematic, unpleasant, dangerous, etc. Often used in passive constructions. I heard Tom's gotten mixed up with some pretty shady people since he moved to New York City. I don't want you mixing Sarah up with any troublemakers, you hear me?
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
mix someone up with someone else Go to mistake someone for someone
mix something up with something else Go to mistake something for something
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.