My Bias is Showing?! manhwa volume 1 features story by Nabit and art by Eol.

High school teacher Na Aejoon has a secret obsession. He's a total simp for the handsome Choi Siyeol from the popular idol group, A-One! Na Aejoon is so enamored with Siyeol that even his weekends are devoted to fanboying over-and dreaming about-the pop star. While he'd give anything to meet Siyeol even once in his lifetime, he's accepted the fact that it's not going to happen one day. Until it does.

Cast in a variety show, Siyeol is slated to be at Aejoon's school for filming. And what's better than seeing his idol every day? Catching his attention! Suddenly cast as Siyeol's co-star, Aejoon must put on the ultimate act: not showing his rabid fan side, lest he creep Siyeol out. But as the two grow closer, keeping secrets will become more of a challenge-for both of them.