This comic consists entirely of a couple of characters sitting around talking. And it's really good. The punchline doesn't even have the rhythm of a punchline. It just sounds like a thing TJ would say.
It would probably be creepy to start shipping these two (though Luann has never shied away from shocking inappropriateness before), but I'd absolutely support an overhaul of the comic in which all the other characters are jettisoned, while TJ and Shannon move to Las Vegas together and try to make it on their own in the big city.