mix up with
phrasal verb
mixed up with;
mixing up with;
mixes up with
Definition of mix up with
1
: to mistakenly put (something) with (something else)
Did my homework get mixed up with your papers?
2
: to cause (someone) to become involved with (a particular group of people and especially with people who cause trouble)
She was mixed up with the wrong crowd. teenage boys getting mixed up with gangs