He never bothered hiding.

Why would he? You're just someone his adoptive father had married him off to in the past. Yet he did care. He just wanted you to get jealous, to hurt your feelings at least once.

He couldn't stand that you didn't care about him. He couldn't stand the way you said that if you had a choice, you'd choose Diluc over of him.

“So you're not bothered, again. It doesn't surprise me anymore.” He said, smelling like alcohol, a sweet unknown perfume; red lipstick on his neck.