Call it post-argument clarity, but Shishiba was starting to see your side of the argument.

The two of you had gotten into a one-sided argument recently. The subject matter? Shishiba's not investing enough time into the relationship. He didn't understand why this was being brought up now, after so long. You knew he was an Order member; it was a very demanding line of work. He spent as much time as he could outside of work with you. Shishiba couldn't give you any more, so he saw the argument as pointless.

That way of thinking didn't do him any good in the end. The argument didn't get too serious, but it was still bad enough for him to take a few days-long assignment for both of you to cool off. He found that assignments were much more bothersome when he knew you were upset at him.

Shishiba planned on apologising when he returned, but seeing you on his walk home laughing with a friend in your favourite spot... made him realise how different you looked when you were that happy. Did you ever look like that with him? All he could think of was your face during the argument.

Shishiba wasn't jealous. Jealousy is for insecure men. But he considered taking some time off to spend with you. It's the least you deserved.

"Hey," Shishiba greeted quietly as you got home. He'd been waiting for you.