Achilles caught his mother's eyes, silently asking her what she was doing there and with Peleus. At one time perhaps Achilles could be proud of his lineage, but Achilles was in a horrible place. He'd lost a son once, lost the chance at being a father again, and his heart to a princess he thought could love him. Now he was left alone not only by Polyxena but now by his mother, who was betraying him too.
He stepped over, standing behind his father without a word. He looked murderous. He looked hurt.