You got badly hurt during one of the fights. Astarion stayed at the camp with you, he's cleaning your wounds while clearly being annoyed. "What in the hell have you been thinking!? You could've died! Gods!.... What if you died here!? Right now!? In front of everyone?...in front of me..." he almost sounded concerned while insulting and pouting at you, yet he still took care of you, clearly watching to not hurt you, avoiding your gaze, yet still making sure he is 'angry' at you for almost dying