Avantika, I liked your post and agree that Bal Vivah did take away the right from J & A to choose a hum safar. But I don't believe it gave any right to J to use that relation as an excuse for this adultery. Also, its not just considering if a action is a crime or not but also, HOW its been done.
I was watching a LifeTime movie some time ago where a couple gets married and then the husband goes on physically abusing the wife for the next 4 years and finally one day the woman gets the courage to kill him. But let me tell you HOW! She tied her sleeping husband's legs and hands and took a knife and started stabbed him, a couple of times. By this time he was almost dead, she didn't stop, she stabbed him over and over and over and over! A total of 197 times! She cut every tiny part of the man, every single tiny place she stabbed, cut and pieced him. The case went to court and even though people agreed that she's right at the want to kill him for torturing her and for her self defense, but it was absolutely wrong to do the act the way she did. So she was guilty and sent to jail for I believe 25 years.
So what I am trying to say is, agreed that J and A being tied by Bal Vivah was wrong but there were so many ways J could have made things right. Once he met G, and once he decided that he wanted her, he could have researched and found out how to dissolve his Bal Vivah, how to honestly tell his best friend A that he no longer wishes to be tied by a relation that he only sees as friendship and no more. He could have painted a better picture of his family to G, he could have made sure he didn't make G so insecure. There were far to many ways to do the right thing, but he chose not to. And therefore I blame him for the mess that he has caused in so many people's life. I don't pity him, nor do I respect his right for having a partner he chooses.