"... Right. There's supposed to be multiple types of love. 3? 5?" Thanatos doesn't know much about it. Such topics aren't brought up or taught in the House of Hades, and on the surface, Thanatos just sees the grieving anger directed towards him or the rare relief that their loved one is no longer in pain.

Thanatos sighs. All that means is that, yes, he probably loves Zagreus in some fashion, but he still doesn't know what it means beyond that. ... Does his confusion mean that he's also considering a romantic relationship as a possibility? What? He's Death Incarnate. And incomplete on top of that. "What a mess."