Didn’t we already go through this in the 60’s, 70’s, 80’s...
I’ve known two couples, one in the 1970s and one in the 2010s, who decided that they should get involved in this. ‘Open marriage’ was the 70s version, ‘The Lifestyle’ in the 2010s. ‘Lunacy’ is what I called it both times, and my dire predictions were hooted down. They had evolved beyond jealousy don’t you know.
It took maybe a year for the 70s marriage to blow up. Ironically enough the wife, who had instigated the whole thing, is the one who was driven crazy with jealousy. In the 2000s the husband was pushing it and the wife went along. That lasted maybe two years before the husband was caught “cheating” (adultery has rules, who knew?) by meeting up with someone on his own time and the wife filed for divorce. I was two for two and insufferable in my gloating.