decide between (someone or something)
To choose someone or something when given two options. Holly and Jack are both such good candidates for the job that I'm having a hard time deciding between them.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
decide between (someone and someone else)and decide between (something and something else)
to choose one from two people; to choose one from two things. I could not decide between Tom and Wally. We could not decide between those two.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.