fall in with
US /fɔːl ɪn wɪθ/
UK /fɔːl ɪn wɪθ/

1.
to agree with or accept a plan, suggestion, or person
:
•
I'm sure she'll fall in with our plans.
•
He tends to fall in with whatever the majority decides.
2.
to meet someone by chance and become involved with them
:
•
He fell in with a bad crowd and started getting into trouble.
•
On his travels, he fell in with a group of artists.