Clark installs a really big TV without Lois' knowledge. Lois realizes that it's not her house, it's their house and is as cool with it as she can be. Possible crisis averted - and another hurdle successfully negotiated.
Mattie all but demands an answer to the question "Why aren't you married?" I think that's the next big hurdle in their shared path. That, and responding to Mattie's comment that they "didn't get it right" the first time. Room for more angst there, maybe?
I think - and I have no advance knowledge - that the last chapter will open with a quick courthouse wedding followed by an extended honeymoon somewhere very private while Martha watches over Mattie and JP. It would be a fitting conclusion to a tale of Lois and Clark reconnecting with, forgiving, confessing to, more forgiving, learning from and with, growing, and adjusting to each other. Of course, the mayor might have a monkey wrench or two to throw at our favorite couple, despite the assurance that there is no A-plot (action plot) in your story.
Keep them coming, Annie! I'm ready for the next chapter.