The moment Percy saw the expression on Emerson's face when he was looked at, told everything he needed to know about how Daphne's father felt about him. His own face darkened and steeled with anger, his eyes narrowing in an automatic reaction. Who was Emerson to judge? Locked in jail for being a Death Eater! It didn't matter to Percy that Daphne was sitting right there, he wasn't going to pretend that he was even a little alright with this.
When Emerson asked him to comfort Daphne, Percy almost felt like not doing it, just to spite him, his hands tightening into fists. Finally, Percy turned to Daphne and wrapped his arms around her, patting her gently upon the back. "It's alright," he said, though he wanted to add 'He's not worth it.