He's a weapon. A weapon made just for her and more precise than anything else the Capitol could have created. Her nails dig into the palms of her hands and she can't lash out at Peeta. That's too far even if there's anger welling up inside her at his words.

"Because I have to do something, Peeta! I didn't ask for any of this to happen to Prim, to me, to us." He should know that, he needs to know that and her voice has a layer of urgency to it. "I did everything I could."