my husband will most likely never make a definitive decision.
its either going to come from me, or the ow will leave him.
Of course. We humans are, at the end of the day, basically "path-of-least-resistance" creatures, and if we're not forced to upset our own status quo, rarely will we upset it on our own. Especially if it's "working" for us, but even in cases where it's downright DYSFUNCTIONAL. It's just basic "a body in motion tends to stay in motion" stuff.
Add to that, that if he ever returns to the marriage only because the OW left him, you won't have really solved anything.