Yes, it can be.
I can say that from experience... I won't give details, but cheating did occur in my relationship. It was a wake up call, and made us confront all of our weak points and approaching problems in our relationship. We had been growing apart, and had concerns and worries and just.. felt strained
We were together, but not together at heart. It didn't occur because of selfish want, but out of dazed and sad confusion.
So... after it occured, we changed quite a bit. We re-evaluated EVERYTHING. We can't live without each other, so we basically recreated our relationship
We found all the problems and solved them.
Thanks to that horrible and emotional time, we really are closer than ever. We're engaged now, and I can't imagine being with anyone else
Cheating wasn't an end for us, it was a beginning. It's almost as if the old "us" died and a new, wiser and more complete one emerged.
hard to explain, to really severe critics out there. But just to comment, I say Yes, it's possible. Most couldn't or wouldn't do it, but... that's a different issue
(I would say that it depends on the details of the cheating, yes: WHY and HOW it happened. If someone slept with someone else for fun, of course I wouldn't want to forgive. But in a case like mine, it was more based on a collapsing of our stability itself... so it wasn't as selfish or as intentional an act. I'd explain more, but I don't want to get too deep into details of such a personal thing
)