Tbh it might just be because he's always putting up a goofy guy act in front of her so she'll stop feeling scared she probably never gets to see the real him. Also I'm ready to throw hands with the mom cus he literally defended his sister from getting beat and he got repaid with his sister avoiding him and his mom accusing him of being insensitive and just like their dad like wtf
She's grown adult now, I dont know if you have siblings but it's perfectly normal for a pair of teen siblings to have big issues/fight/be distant and then get along better as adults.
Ofc the hypothesis of @elidel could be true as well but that would be a shame honestly :/
I was also soo angry with the lil sis, but the mom kinda have a point, Youngchan was a boy with crazy stupid force, a middle school girl (so 11-15 yo) already experiences violence from one of the man supposed to care for her and witness the only other guy of her life perform the exact same violence.
A lot of women at some point thought, if "he can do it to someone else, what if i'm the one who upset him ? will he do it to me?"
And now i feel sorry for everyone really because all of them were just babies :/
But what upset me the most is that what Hyunsoo said kinda triggered those memories ?? like babe no you shoulnd'nt relate that bum ass abusive bf of his mom, ur nothing like him!!!
I mean… isn’t he in a good relationship with his sister now right? They have that skii picture and they looked so close.