Airi didn't help her case. I understand why she would do that but here, it's just a pick your poison situation, the blackmail possesive girl or the manipulative egocentric girl. You know that both are bitch that do something for bad reasons and you know that you had to choose a side because the end of the chapter told you that Hina will not consider break up of Airi like that. If anything, that even make her want to switch the position. Tl;dr : Airi is a bitch, Glasses-chan is a bitch and Hina is starting to become Airi. The only one you can pity are Airi's friends and Yuu because all of them are either clueless or fed up with lies.
God fuck this manga really messes with my heart. Is everybody just fucked up here? I still seriously hope Ai will actually get her comeuppance and won't just get away with everything scot-free though.