Why would it have to end?
You are poly-wired. Does that mean that it has to be your way or not at all?
My husband was very much against me having another man in my life. He was good with a woman - but not a man. We talked. We discussed. I DID NOT push.
Eventually, he said, ok... fine... lets try this, but we need to go slow.
And then he found someone. And totally understands WHY I'm looking for more.
But what I don't get is why your marriage has to END because you want another man? Is there someone specific waiting in the wings? Or are you just so very impatient that you can't talk to him, give him resources, give him time to process and work through what ever he needs to work through?
He may surprise you in the end. But by saying it has to end if it doesn't happen your way is a hard-line position that may hurt YOU more. And your children.
I would suggest that you take the time, read some books, point him in some good directions and be patient.
That's my experience, anyhow