Not to say Skylar is perfect himself or anything, he can let his anger get the better of him a lot, but Cirrus was mainly the one lying and manipulating and isolating him for a good while, and yeah Cirrus's backstory is sad and all that but that's not an excuse for how he's acted in the past and he needs to learn to connect with Skylar in a healthier way.
He only apologized when he got caught so it still doesn't make up for everything he's done and he definitely needs to work on forming a more honest an healthy relationship with Skylar. Skylar had a pretty good reason to be slow to trust after being manipulated and sexually assaulted the last time he was open about his emotions to the person he loved, especially with how Cirrus treated him in the beginning. Not saying he shouldn't have tried to reach out more himself once they were in a relationship or that it's not a good thing he's reaching out now, but after what happened to him before with his former best friend finding out Cirrus was manipulating and lying to him in regards to such a big aspect of their relationship would be super triggering for him so his response at the time was understandable even if it wasn't the best way to react.
Made up for it how? He never stopped lying about it and hiding it, Skylar even gave him a chance to be honest about it during the confrontation and he still lied. Cirrus got nicer to Skylar as he processed his feelings and realized he would push Skylar away if he kept his bad behaviour up, but that doesn't erase his initial actions. He didn't address those prior actions or try to own up to them or undo any damage they might have caused, but rather ignored them for the most part and as a result his insecurities built up because their relationship was largely built on those deceptions to begin with. To be blunt a lot of what Cirrus did was abusive, trying to isolate him from his friends out of jealousy, manipulating him and lying to him to get him to act the way Cirrus wanted in order to appease his own insecurities. As things continued he learned to actually care about how Skylar felt because he loved Skylar and started treating him better, but that doesn't mean he's made up for what he did before when he was content to brush everything under the rug until he was forced to admit it. His biggest flaw has been his possessiveness which comes from a place of insecurity, and he has started to improve on that front but he still has a way to go. Skylar has every right to be mad about what he did, he didn't do anything wrong by getting angry or even pushing Cirrus away at first because he needed space, the only thing he did wrong in that moment was bringing up Cirrus's past in such a harsh way when lashing out. Skylar's biggest flaw is his difficulty trusting people and making genuine personal connections as well as his tendency to lash out when he feels cornered or betrayed, but he has at least been making a consistent effort to reach out and connect more with people throughout the series not just with Cirrus but with others as well, which is why he's able to take this step and reach out to Cirrus now. It shows how far he's come. But I'm hoping it's treated as that and not a one sided thing where he needs to be the only one or main one apologizing, and I especially don't think he should apologize for getting angry at the time. If he does apologize himself then it should just be for the harsh things he said, not for being mad aboutwwhat Cirrus did or for needing time to process everything afterwards beforeccoming back around. I'm hoping them eventually making up is more about him reaching out and forgiving Cirrus and Cirrus actually deciding to be open and honest with him as a result, not because he got caught but because he doesn't want their relationship to be built on lies and manipulation and toxic possessiveness anymore. Especially since what Cirrus needs is someone who will accept him for how he truly is, including all the ugly bits, and what Skylar needs is someone who is willing to be open and honest with him and trust him rather than someone who will let their insecurities drive their actions and use his love for them as a way to control and hurt him.
Dudette, read ch 125 and maybe u will get it. Also don’t forget that Skylar nearly disfigured Cirrus’ face. And every single time Cirrus wanted to know more about Skylar’s past the latter tried to dismiss it. Skylar has his flaws too and these flaws aren’t worse or less than Cirrus’. They are on the same level.

Ngl Skylar had every reason to be mad, even if he was a bit cruel with his words when he first reacted I hope the story doesn't make it one-sided whenever they manage to make up, like having Skylar act like he's the one who fucked up. Cirrus was kind of a huge piece of shit in the beginning, lying and manipulating Skylar and Chan-il in order to get what he wanted, and Skylar had every right to be upset about that. It was definitely Cirrus who was in the wrong for what he did and imo it should be more about Skylar forgiving him. Guess we'll see if that's how the story is handled or not.