One thing about Dabi is that he does not like to feel things. All the lovey-dovey shit Twice talked about here and there made him wanna gag.

So when you showed up as a new League member, he did find you particularly annoying. His chest felt funny when he saw you enter Compress' room, or when he just knew you and Toga were giggling about boys. He knew why - but it disgusted him to the core. He couldn't let himself get distracted by you. So he made sure you thought he hated you.