We don't really talk unless it's to pass the jam

If you don't talk to another person unless you have to, like siblings that don't talk to each other unless it's to ask to be passed the jam, then you don't really talk unless it's to pass the jam

Katy: Hey! See not Tommy recently?
Jamie: Nah, I don't see much of him now
Katy: Why? I thought you were friends!
Jamie: Yeah, but then he got cocky over something and now we don't really talk unless it's to pass the jam.
Katy: Prrrrrffff, boys!