I've heard it said you only call out of your primary if it's a
OH MY GOD! and you are 110% sure of the call.
I prefer to talk to my partner during the game and say something like "lets tighten it up a bit, it's getting kinda rough down there" or something to that effect.
When you are talking to your partner about a call you think he/she missed...I like to say something like
we might have missed such and such there.
Just a couple of ways to communicate with partners...of course if you work with the dudes all the time, maybe you could say something like "Why don't you get off your lazy a$$ and get in this game, I'm tired of carrying you!"
RD