Hat off to Doyak-nim for her genius on creating such a complex story.
first, she did make my believe that Ian felt nothing (doesn't love TJ) anymore. But the more i read, the more i change my mind. he wants to leave not because he doesn't love him, (obviously Ian is too kind to love TJ no matter what has done to him) but more like something underneath that make both of them have to buried their true feeling and lack of healthy communication . At least what I read in previous ep is Ian's guilt towards Tj (excited to see more on this part) Ian is the type of person who felt guilty easily even tho he's not at fault. I think he might afraid to ruined what TJ's life or what he has build up until now due to Ian wants a normal life. so he try to leave, ian want to disappear for 3-4 years but i didn't see forever written anywhere or come from his mouth. It more like Ian want to re-defined their relationship than don't want Tj in his life. After all they are family.
I get it tho, it hard to stop loving someone because they change. Ian still love him because he still love TJ that he remembered. After all it's the same person.
My prediction is ss1 will be mainly about TJ&Ian but ss2 tho Jo will get more screen time for sure and im looking forward to it. Maybe in ss2 we will see Ian living a normal life with Jo like he always wanted it. But ss3? i have to give up here 
