For those who are confused. Apparently, something happened with Yuta and Seunghyun in the past. It seems that Seunghyun had lured him, perhaps with the promise of getting him out of that place where he was being prostituted, and that Yuta even fell in love with him in some point. But he ultimately abandoned him and never saved him from that place. And that's why he says he was torn apart and fragmented for a long time until he managed to marry that powerful old man.
And that's why the memory comes up, which is a flashback of both of them, of Yuta remembering when he called Seunghyun after being abused and hurt by the son of his future husband (who is now dead). And remembering that apparently at that time, Seunghyun told him to call him if anything happened, but didn't speak and hung up, feeling foolish for thinking that a Yakuza would actually care about anything that happened to him. (Possibly this memory is from before Seunghyun made the promise to get him out of there or whatever.)
And then comes the memory of Seunghyun, who, after that missed call from Yuta, finally went to the brothel (suspecting it was Yuta who made the call) and found him all hurt.
Apparently despite the mutual resentment they have at the time. Seunghyun is haunted by something that makes him feel guilty or bad. Possibly abandoning Yuta there and that everything that Yuta suffered and shaped the current Yuta could have been avoided by him.
For those who are confused. Apparently, something happened with Yuta and Seunghyun in the past. It seems that Seunghyun had lured him, perhaps with the promise of getting him out of that place where he was being prostituted, and that Yuta even fell in love with him in some point. But he ultimately abandoned him and never saved him from that place. And that's why he says he was torn apart and fragmented for a long time until he managed to marry that powerful old man.
And that's why the memory comes up, which is a flashback of both of them, of Yuta remembering when he called Seunghyun after being abused and hurt by the son of his future husband (who is now dead). And remembering that apparently at that time, Seunghyun told him to call him if anything happened, but didn't speak and hung up, feeling foolish for thinking that a Yakuza would actually care about anything that happened to him. (Possibly this memory is from before Seunghyun made the promise to get him out of there or whatever.)
And then comes the memory of Seunghyun, who, after that missed call from Yuta, finally went to the brothel (suspecting it was Yuta who made the call) and found him all hurt.
Apparently despite the mutual resentment they have at the time. Seunghyun is haunted by something that makes him feel guilty or bad. Possibly abandoning Yuta there and that everything that Yuta suffered and shaped the current Yuta could have been avoided by him.