You've got some wonderful posts there yourself,
Lorelyen!
I would add this...
BAYBEE:
If it becomes an emotional affair or even a short-term physical affair (fling), that is cheating by the standards of most. Even if there is no future.
Socialising as friends is not cheating IMO so long as you would feel comfortable telling your husband and/or bringing your husband if he wanted to come. If the tables were turned and your husband had met a friendly new acquaintance of unknown intention or honour (LOL) but you had not, would you want to be informed or perhaps come with to meet, at least on occasion? He may completely trust you but simply want to be included at times. So...are you honouring that trust?
If you prefer to have an open relationship so you can be involved with others whilst raising your kids together, you definitely need to have that conversation first. If your husband is not down with it (and most probably are not), then you'd need to decide if you can really be in a marriage faithfully...or not.
There are a lot of moving parts and only you can decide for you. But IMO it's best done with a clear head. You say there's no future. Can you remain strictly friends? It's not clear if you can do that. So are you willing to hurt your husband to end the marriage? (You should always expect to be caught or found out).
Or would you prefer to stay, to think about it, and/or to possibly end it but on good terms? These are all preferable to cheating on a committed partner.
I still recommend talking to your partner about the need for more love and interaction and intimacy. IMO you should tell him (gently) you want to go to a counselor and talk. If all this and counseling gets you nowhere, then you could ask him why, and/or if he wants an open relationship. Maybe he doesn't but he's depressed or needs help himself, in order to make things right between you.
If you're not well suited no matter what but must stay together, perhaps you can come to some agreement, but I will say that generally most relationships don't survive infidelity. And long-term lack of intimacy is a big reason for a portion of that infidelity, so you owe to your husband to discuss this issue...as his lack of touch, engagement, and connection has brought you to the brink.
I do wish you all the best of luck & I hope you keep us posted
Peace & blessings
7L