I wanted to read ahead of the anime, but ended up starting the manga from the beginning:
In the anime, I feel like what was supposed to be romantic is an annoying nuisance at best, but in the manga I can see MC slowly becoming more… aware with time.
By the end of vol 4 it became believable to me. Disclaimer: maybe anime had that too and I’m just blind.
Also, I’m in the middle of this audiobook:
Content warnings lmao (edited)
EDIT after it was pointed out that I failed at explaining the roles here 
The couple is married for 8 years now and they’ve never met face to face. She sends him a letter for the first time ever asking for a divorce, but he gets a bit offended (even though he doesn’t care about this marriage either), proceeds to learn and believe bad rumors about her, comes to her bedroom in the middle of the night and proposes a bet.
The blurb should really mention “bet” is “he will allow them to divorce if, after a month of trying, she doesn’t get pregnant. Otherwise they’ll be married forever”.
I feel like many of us would go “ewww what” and for some of us this might be a hard no-no.
So she doesn’t want it and he doesn’t want it either. Worse than that, in his POV he’s also assuming she’s sleeping around in general and with his father in particular, and that doesn’t stop him from going ahead with it, ewww (also, she isn’t!!). While her thoughts of “well, it’s not like getting pregnant is easy, other ladies complain about it, so maybe a month will not be enough” made me choke and Google birth control spoiler there and then
Why we start like this is not clear - the story is fully in the scheming/territory management and snarky banter between her and his father.
It’s probably there to serve as an excuse for sexy times in the future… Who knows, maybe the second half of the book will be spent in sex dungeons after all?
Anyhow, the audiobook is amazing. It’s narrated by a guy, and he’s speedrunning worldbuilding/narration so fast, I literally can’t multitask while listening. This will be a real 5/5 for learning. I’d give it 6 now that I saw a Japanese comment on Audible complaining that it was too fast for audiobook.
As for now, most of it is snarky banter (between MC and her father-in-law), the high tempo and the voices he makes make it absolutely hilarious.