It was a starting point when the boy didn't make a move and kept his cool. Achilles however was still reeling. His glare was a heavy one showing little emotion towards Neoptolemus that wasn't pure rage.
"I do not wish to make an enemy of you, Neoptolemus." If his son thought he was greater than his own father he was gravely mistaken. "You have no idea what you're asking for by threatening me. Continue talking down to me and you will see my wrath."