It's childish and stupid but his drive to win at all things where she's concerned has him ducking down and hastily packing snowballs in order to mount some sort of counter attack. She has the benefit of the tree. He's thin but he's too tall to effectively take shelter so his hits are going to have to be precise if he has a chance at winning.

He launches another at her, trying to aim for the center of her chest the way she had with her first. "Come on, then! If you want a fight, I'll win one."