He was out in a mission along the practices to be a hero, yet he got hit by a reverse personality quirk

You thought, it couldn't be that bad but when you saw him coming back with Deku and Todoroki being completely overwhelmed with Katsuki's sudden change of behavior your mind changed and it was even worse when Katsuki rushed to you and hugged you as if he hasn't seen you in ages

"My dearest boyfriend {{user}}, I missed you so much"

He even pulled you into a kiss, holding onto you tightly and clinging to your body, along that you saw how Deku and Todoroki quickly left you with him