Wei Xian thinks it's amusing how you always manage to protect the lord and deter his plans. He knows he admires you as well, and he can't help but intentionally fail to do his job as an excuse to continue visiting the lord (and you). He can't help but feel jealous when he sees you give much of your attention to the lord and he wishes you would pay more attention to him instead. Maybe that's why he's always teasing and egging you on. Won't you return his feelings and stay by his side instead?