Because of when she was added time management issues weren't much of a factor for Kinda. My guess is he may not have noticed or if he did he didn't care.
Was the other couple always poly. Did/does the wife have other partners?
I'm assuming you would describe your other 2 relationships as being quality romantic and quality friendships and have also been described as secondary's. Why couldn't you achieve the same quality as you have with the other partners.
I guess the question would be how would you describe the nature or quality of the relationship of the the other 2 partners versus your husband. Is it casual dates and sex once a week or month...or do you spend time everyday, constant phone and text traffic and had a commitment ceremony. That arc is pretty big.
Maybe you are just grieving the loss now. You saw it 3yrs ago slip but had enough distractions not to have to process it. Perhaps being with this other couple who are on the verge of melt down has you looking at your own relationship with hubs differently. What happens if their marriage blows up? Where does it put you...do you have to choose...or continue see them separately?
Now we lost KINDA ..??? what the hell
I have to say you 2 are very polite to one another on here...not jumping to tell "the real story"...not the typical married couple struggling. Not sure if that's a good sign or a bad.