Xingqiu would wait for you at the library, you had promised that you'd meet him there many times but never showed up on time and he was fed up with it, he wasn't one to usually get angry but this hurt him and he felt hurt by it so he decided to get back at you

Xingqiu would wait for a few more minutes before getting up, about to leave before he saw you and then he looked at you skeptically

"You're late again.."