Strongly suspect DH is having an affair, no solid proof.
He won’t admit it. Even with evidence, I think he’d deny. I’ve suggested splitting several times over the past few years as we’ve had our struggles- he never wants to, hates that I suggest it.
But why? OW is single, no kids.
What’s he waiting for? Surely the OW must be dreaming and hoping for this, so why doesn’t he take the out?