Yes, and all the psychological abuse from everyone in his life.
It was also one sided. So, Kwon was bound to the broken Sejin, but Sejin didn't get any of Kwon's memories. Quite the mess.
Oh yeah, I think the author should have put what Sejin saw into Ido memories. But it was too late Sejin KS himself. I think after the bonding Ido would have an idea how to deal with Sejin family and his brother.
Sejin said "Who would have thought I'd feel nothing". Clearly the bond didn't work properly. He didn't get Ido's memories or emotions. Ido on the other hand, had no idea how to deal with the flood of emotions and memories. You can see it destroying him.
Oh I think when Ido bonded with him if it was true they would share memories then he would have had saw in Sejins memories the sexual assault?