Chapters 80, 111-113. The parents are already cool and Heeso was present at their wedding. Kyungsoo is Byul's godfather , so it's very likely that Hyseung is Yoo Bin's godparent as well. Which technically makes... Furrina
Again no one said they should be judging each other based on what their parents did (just to be perfectly clear on this ,no kids are judged by anyone for their parent's actions, why are you insistent on this?).... Yamatogirl
The parents have moved on. Why would they talk about things that happened even before the parents got together, let alone before the kids were born, with the kids for no good reason, esp since they have cleared all problems between them.
Weren't their parents married? The blue haired omega mom and dojin's older brother? It'd be kinda weird if they got together (￣∇￣")