So one thing I am curious about is your use of language. There is you, and there is a husband and wife. And you're in a relationship with both. What names do you give your relationships with them? What status do you have with them?
I ask because we're at this point in our group of three. The marriage that I've been in has opened up, widely. Sure, my wife and I are still married. But our language to the woman we're both seeing has been changing. We haven't found the word that makes sense, but ... it's not like there's just ONE relationship, and someone off on the side. AM is part of the fabric of our marriage, just like my wife is part of the fabric of my relationship with AM, and so on. There's THREE relationships, and they are of increasingly equal value. One happens to have state sanctioned rights, but the other two relationships are no less serious or intense.
Does that keep us from feeling jealous, wanting more time with a person we aren't seeing enough of, or whatever else? Nah, we experience all that. But we're not protecting the marriage at the expense of the other relationships. It's not more sacred, more special. It's been around LONGER, so that makes certain changes more difficult, at times, but that's different from being more sacred.
Don't know if that helps you at all. From what you write, it seems like you have relationships with each of them, but THEY aren't maintaining their relationship to each other. You could help them with that - set up dates, help wake up the husband and then go away, who knows. But if one couple in a trio isn't working, eventually it screws everyone up, right? Plus, sometimes it's fun to help the couple you're not part of come closer to each other...