You can communicate an entire personality assessment in a raise of the eyebrows.
Giving each other that look that silently says « we need to debrief this as soon as possible. »
And then subtly following each other to the toilet where you talk about how terrible that meeting was.
But giving it enough time in between you both leaving so that it doesn't look too suspicious.
Giving each other pep talks whenever they are needed.
« You can do this, you can wait until 12 before you have lunch. »
Quickly changing the conversation when the colleague you were bitching about enters the room.