obviously he has been hurt bad and at tis age it hurts more because of immaturity and lack of experiance but if he chooses not to be kindI suggest you get away from him before you start getting the same treatment
Love is blind
Duh, she used him.
Balance in these kinds of things is good. But going from one unwise extreme to the opposite end of the spectrum is bad.
Finding the right middle path is hard for many people.
Allowing emotons to blind on to the truth of the situation resulting in apologizing and taking the blame for every trouble even when it originated from the partner. The other extreme is to turn into a hard nut who puts the blame on the other person all the time because they have been burnt. They go from being a victim in relationships to being an abuser in relationships. One extreme to the other.
Well He should change his behavour. But not to the other extreme. If he does that then he is going to be blaming you for every problem that rears it's head in your relationship with him. That will ensure another failed relationship. Encourage him to be balanced, Yeah He should learn a lesson from it in a level headed way. Not allow emotion to cause him to go to the other illogical extreme.
Some people are slow.
He was slow to realize he was being used.
Why does he have ANY contact with his ex? He's with you now! People should leave their ex's in the past unless he has children with her and must coordinate child care.