Eh in this case he was a child who was confused about how to handle his sexuality and suddenly had someone interested in him. His brain wasn't done growing and he was a victim of a pedophile so him being the affair partner really just makes the full grown man who was making the disgusting decision to put his hands on a minor even worse.
But he wasn't a cheater, he was with a man married and (at least how I understood what they said —eng isn't my language) after they left he enjoyed his youth with many friends with benefict. Corret me if I'm wrong, like I said I'm not so good with eng so I might as well miss some points
I would never want to be with someone who was in a relationship with a cheater; ie the third party in a relationship. They could defend themselves all they want but it's just a no for me. I know he was young then but...nope. Just nope.