Hythlodaeus's heart falls at those words. With how short their time here has been, he hasn't yet gotten used to how... finite things are in the mortal world. And what's even worse is hearing his friend speak as though... as though it's a sin to be happy.

Hythlodaeus wraps his arms around Hades protectively, as if trying to shield him - and more; not just shield, but nurture and heal and restore. The thought of anything being otherwise is so wildly alien that he can't even bring himself to think it.

"There is naught wrong with it," he whispers, kissing the top of Hades's head and blinking away his own nascent tears. "There is yet much that I do not understand. But the one thing I know for certain is that there is naught wrong with wishing for love and happiness. And I... I cannot well express how much it devastates me to know you've been denied both for so long."