You could have the timeline running backwards... where divorcees head from a mild distaste to become increasingly bitter towards each other. So much paradoxically so that they decide to share their stuff. Erstwhile arguing even more. But the arguing fades, fades enough for the mistress (who lives in a sub-plot) to feel herself a gooseberry and leave just the husband and wife to get on with being friendlier and friendlier towards each other. This culminates in a reverse commencement of lovemaking, till their acned kids come back from university. The disruption is only temporary as their (the kids) complexions improve and they start going to bed earlier and earlier giving over more time for the couples' said lovemaking. Fast backward a few years and all's rosy; the rosiest it's never been—the kids eventually leave home (through a curious avenue) as the most adorable youngsters and with even more time now on hand; the couples' love for each intensifies to obsession. They're so happy with each other they donate away their wealth, downsize their house and cadge meals from their parents each Sunday. But it's too much, too strong a feeling they have for each other—their life's climax. They call time and decide to part on a high. Only occasionally from thereoff do they admire each other from afar before even that fades to two kids who'd rather dress dolls and hit things with sticks.
Someone on another writing forum I visit has written something similar and she's having a real struggle selling it to any publishers, even though she's previously published. But for self-publishing? Do what you like.
It might be fun as a short story, but I'm not sure it would grab me as a novel-length book. It just seems like it would be really hard to create any real drama or feeling when everything's so deliberately slapstick. Ya know? Could be a fun short, though!
Hmmm,,,Groomsmen bickering over the patterns on the cumberbuns...No---I want to wear a vest!! What's wrong with a bowtie? I do NOT want to walk up the aisle with that slut! She keeps gawking at my guns! I have to agree-a short story would probably be fun, but a novel would be hard to maintain interest.
Is this just an intellectually-based idea you came up with, or is this a story/novel you would enjoy reading if somebody else wrote it? If the latter is the case, then by all means go ahead and write your own version. I believe it was the novelist Anne Rice who said "Write the book you'd want to read yourself." I think that's an excellent piece of advice. If it's just an intellectual idea (hey lets turn Romance on its head) I think you need to think your way through it a bit. What would be the purpose of writing a story like this? To show that traditional Romances are silly? To show that many people have relationships with unsuitable partners that just don't work? That folks get left at the altar several times, despite their best intentions? What would your purpose be? What would you want your readers to 'get' out of this story? There is no reason it wouldn't work, but you'll need to be aware that you won't sell it to Romance afficianados. I think when you come up with a radical sort of Idea like this that you want to turn into a story people will buy, you'll need to have an idea why they would buy it. If you've got one, great. This anti-Romance might be simply fun or enlighteningly bitter. Who knows? However, just coming up with something weird isn't always enough. Hey, lets make our main character a duck who has lips and teeth instead of a beak, who can't swim, can only quack in French and hates water but he falls in love with a whale. Ha ha. Great idea. But ...will it work as a story? Only one way to find out.
I agree with @jannert re. considering purpose/audience, and I'd add - making fun of romance isn't exactly new territory. It's been done a lot of times before, sometimes well, sometimes not. When it's done well, at least to my taste, it tends to come from a romance insider who knows the tropes inside-out and can catch every little detail of the image.
