This is great. Yes, dialogue should do one of three things—and I doff my hat if you can do all three at once: convey exposition, say something about the character, and/or move the story along.

I was just telling a co-writer friend of mine that while he has an ear for funny dialogue, he needs to see if the dialogue makes structural sense. If the dialogue doesn't say or reveal something about a character, it at least has to serve a narrative purpose. So after sitting on our pilot script for a while, I told him that a scene we wrote, while funny, adds nothing to the story and doesn't lead to an eventual payoff. And so out it goes! It happens.