And what about Asriel? They must have been a bit spoiled, a bit stifled, a bit lonely, and also oppressed by their parents' expectations for them. I imagine that little Azzy did not much like being a prince, when it came down to it, and took what opportunity he could to sneak away and have a little fun on his own. Having a playmate in Chara must have been like water in the desert for Azzy. But after almost suffocating under abusive parents Chara must have been a bit dazzled by the freedom that Asriel had, and it went to their head. I think of "Mr. Clean" from Coppola's "Apocalypse Now", drunk on the "light and space" of Vietnam.