Thanks! That might be worth a try. I'll try a couple of other things before that, though:
- delete the localthumbcache.package file
- delete any copies/clones of that household that may still linger in the Gallery - I assume there are a few because I more or less regularly save my households to the Gallery in case anything happens
- use the cheat console to remove the loyal trait
- maybe remove that townie one of them married just in case
- check their likes/dislikes in CAS and disable every single one that might mess with them
If none of this works, I'll try the remove/delete/redownload approach, even though that means all their relationships with other Sims are lost, including friendships, but at this point, that's probably a small price to pay.
In any case, I have decided to keep my playing time with them to a bare minimum = don't play them on every rotation. After almost three years playing this save, I have 18 households with 35 Sims total, and these two have started to feel a bit like a chore even before things got completely out of control. I think that's because some of my other Sims have become way more interesting and have better storylines, so checking in with them only occasionally won't feel like I'm missing out on something.
On a side note: I just found a thread on Reddit that addresses the problem of constant flirting. It seems it is related to Growing Together and the likes/dislikes system. I also just realised I created these two in Spring 2024, not in Fall '23. At that point, I had bought Growing Together (didn't have it when I created my first household), so maybe there's a connection there 🧐 It still doesn't explain why one of them got married off-screen, though.
I'm usually fine with the madness the game throws at me, like finding out one of my Sims had an alien baby after I left him. I usually roll with these, but in this case... nope. There's only so much madness I'm willing to handle.