This is the point where I put a series on hold and wait for the END notice. For me, things should just get wrapped up. If the premise is they are married, in the manner people typically were at that time, then she's broaching the central reason why they are together. If these two are too embarrassed to do what marriage put them together for then there's nothing more to say.
At times I wonder why some authors constrain themselves to varying the same joke. Is it like an étude? I'm not trying to be negative though I know that sounds negative. I would think that having things develop, or even other random humor, would be easier to maintain interest (even for the author).