It takes Hythlodaeus several moments to work out what Hades is saying. He's wrapped his arms around his friend, holding him as he cries; the apology for the past elicits a soft, fond huff from Hythlodaeus - it's hardly Hades's fault, and besides those worries are dispelled now. But then...

Hythlodaeus's brain slowly constructs the chain of reasoning ("if" means a conditional, a proposition of a situation different from the current reality, and Hades mentioned his name, so...) - and then he blushes, his whole face going red. And stares down at Hades, mouth slightly open as he fails to form any words for a response.