My FWH and I were "soulmates". I thought...
We were ecstatically happy - I thought we were, and maybe we actually were.
For 5 years, we were inseparable. Paupers, living off love. Trying to conceive - going through miscarriage, fertility, and adoption hell. But together.
Then the firs child came, then 2 more. Fast. And he couldn't "hang". I was paying too much attention to them. (3 boys ages 2 months, 12 months, and 3 1/2 years).
I don't know when his cheating started. He looked at porn, and (says) he was with one prostitute one time.
I have no idea if that is the whole story. I agree with the other posters who say we can never REALLY know. Which is really shitty for us AND also shitty for a truly remorseful spouse.
I think all we can do is to look deep into ourselves and ask how we can move forward with this person.
If we cannot - then we cannot.
If we can, we must determine what we must have to feel safe, and require that of our partner.
We must stick to that in the event of repeat offenses.
My case was a bit different than some, because his health was failing and he didn't actually have the opportunity to repeat offend. Not much consolation for me. I "won" by default.
I decided to stay. For many reasons. Age, finances, kids with issues, commitment - not necessarily in that order. But I stayed.
I believe my FWH did not reoffend. But I have no way of knowing. Not with a lie detector, or anything short of a personal audience with God telling me so!
I say all this to say that I believe we have to determine what we are willing to risk, do the hard work together, and move forward in whatever direction it takes us.
But we can never REALLY know. There are no guarantees.
The only thing we truly have/know is ourselves.
But, I will say - on a positive note - that I do believe there are people who overcome this hell. I have "met" former waywards on this site who seem to be some of the best people around.
I guess we all just have to decide what we need to move forward, and what we are willing to risk.
I wish you peace of mind. It's so very hard.