Hye-sung crashed out is valid. This grandma issue and the grape issue are the reasons why I don't like Dojin. Dojin betrayed Hye-sung by having connections with his mom. Byul can never have connections with his grandma if Dojin did not start connecting with her.
I dunno why he do this shit. It's clear that Hye-sung don't want anything from his mother. I get that Dojin take pity on Hye-sung's mom. But, why not only give her something. Why talk with her behind Hye-sung's back? He is really a shit. He said he love Hye-sung so much but he can't even respect his decisions.
I'm not really mad with Hye-sung's mom, her not apologising is her own decision as well. She said, she don't regret leaving because of her shit experience with Hye-sung's dad. Because of this, I really can see that they are mother and son. They have the same attitude. With this type of person, it is better to let them on their own. Do not meddle. Because if you do, your just disrespecting their decisions.