Responses

Right, and he just dumps it at all once so casually like he wants to get it off his chest but doesn't actually see how wrong he was for that. Like he said it so matter-of-factly like he expected her to be like "thank you for telling me. I'll go to talk to chan-il" He doesn't even apologise..
It's like he recognizes what actions hurt people but doesn't understand their response to being hurt. Like skylar didn't except his apology and cirrus was mad enough at him for not forgiving him to give him a bloody nose. I really hope he learns accountability soon
When I read the raws, I didn't understand why Ri-in's angry with Cirrus when she knew exactly that Cirrus likes Skylar and she was in agreement to go out with Chan-il, so I think the slap was confusing. But now that I read the translation, I think I get it.
Ri-in agreed to date with Chan-il with a condition that Chan-il should never know that Ri-in and Cirrus were actually besties/cousins/closer than a mere acquaintance. Iirc Cirrus asked Ri-in to just said that they went to a tutoring school together. And I think we were also shown that their closeness/friendship had always been a roadblock for their previous exes (exes thought they were dating). My guess is Ri-in thought Cirrus asked for them to not revealing their true relationship for that--when actually it was to his little plan regarding Skylar.
But that arrangement made the scene with the two of them that Chan-il witnessed exactly looked like an affair. And instead of clarifying the mess he created to Chan-il, Cirrus decided to drop all of the burden to Ri-in--the one he asked to shut her mouth regarding their relationship--and potentially jeopardizing her relationship without giving a single help to defuse the situation. In addition to that, now Cirrus infodumped her the truth about Skylar and ASKED HER to relay the message to Chan-il. Not to mention inside it also some info that's personal to Skylar--Skylar should be the one who told Chan-il he loved him before, not Ri-in. Cirrus relaying these info to Ri-in as an explanation when he himself making excuse as to why he won't confront Chan-il himself with him would make Ri-in looks like a blabbermouth to save her own relationship.
It feels like Cirrus asked her to drop paints on the floor together and then gave her the mop and bucket to clean it and asked her to blame him when adults came angry, but Cirrus will be nowhere to see instead of cleaning together and took responsibility with her. It's a shitty thing to do to your bestfriend.