It's kinda unreadable. "He often insults me, but I don't show it on my face" doesn't make sense. Probably just 'annoys me' right?
I thought that too. From the rest of the translation, I'd guess it's a subjectless (and objectless) sentence. Machine translations assign pronouns to subjectless sentences pretty randomly, so you should never trust pronouns in machine translated Japanese text.
I'd have the translator/editor go back and see if, "I often insult him, but still, although I don't show it on my face, I really like him." better matches the story as a whole.
I can't really imagine an otaku MC insulting the gal heroine unless the otaku has a lot of growing up to do in the story. And from the title, this story looks more to be more about how the gal becomes more honest with her own feelings.