I started reading the first chapter, as I progressed I thought "the couple has been together for a while, I guess they never had sex" but then they did and then it went into....swinging, which is just insane, I tried to give it a chance as I felt a sense of disgust growing within me, this is not healthy.
I can't talk for experience, but I have read how there are couples that can't trasform that passion from the flame of that first love into affection, the sort of love you feel for your family, something for the long term, they may see the passion go away and they assume that love is over and so they need that excitement again.......but that's not how it goes:
is like winning the lottery and then trying to chase that high again instead of being happy with the money that you got.
I read the first 4 chapters and I find this work misanthropic, on top of it is already posed like many of these kind of works to not actually address the problem is showing but lean into it for fetish reasons.
"Ueno-kun wa Kaihatsuzumi" for example, even if it took over 50 chapters, seems to have a protagonist who is finally going to stand up for himself against the bullying and sexual harassment he received, hopefully it continues on this trend, but it could have easily just kept on going like that to appeal to people who like femdom and humiliation play.