Miles is the Bad Guy

[ColoredButtholeFlaps]

After multiple viewings one thing I've come to realize is that Miles is actually the bad influence. I hope that he changed as a person by the end. There is hope for that and that he stays committed to the relationship with Mia.

Points
It was found out that Miles cheated on his previous wife. Not sure if the wife ever found out, but probably moved the divorce further.
Jack was cheating, but he wasn't married, so while a jerk move, not necessarily against the religion he converted to.
I also believe this was Jack's first time cheating and he wasn't the serial philanderer he was made out to me. Just the way he fell in love with Stephanie and how everything was different to him. he would have experienced that feeling with anyone he cheated with.
Obvious - Miles stealing money from his mom