I feel like you are 100000% right. Plus him wanting to be friends with her again just so *he* can feel better is, in my opinion, more selfish than anything she did. I don’t understand how people in these comments are switching up on mc so fast just because she took the chance to be with someone she loved. HE is the one that initiated the relationship in the first place, knowing she truly loved him. He used that affection for his own good. There is nothing wrong with wanting to be around the person you love, who is also your friend, who also never protested or rejected her feelings/expressed discomfort at her actions. she never pushed him into a relationship, or crossed any lines or boundaries. She simply saw a chance to be around the person she loved, and took it. Just because she had a selfish reason behind it shouldn’t take away from the selflessness of her actions of not only SAVING his dad’s life, but also spending time taking care of him after, as well as helping his sister with her studies. She truly loved him, and I see nothing wrong with her wanting to try to make that love reciprocated. He hurt her more than her “impure” actions could have ever hurt him.
I seriously do not thing what she did was anywhere near the level of being as self absorbed as her ex is. Looking at it deeper her ex is so oddly conceited that preserving his own self-image of being "kind" is more important than than his whole charade of dishonesty for YEARS taking advantage of the girl who he knows likes him. That is 100x more of a redflag than what the mc did.
If we break it down what she did is not out of the ordinary when you like someone you do nice things of them. She NEVER expected the ex to be with in her in some kind of exchange but the only thing she did that was "selfish" was use the coincidence of saving his dad to be more involved in her crushes life. But she not once says or alluded to that she believed "because I saved your dad you he should be with me".
Is it pretty privilege of the ex cause the switch up on him is crazy. These last chapters make him seem even worse.