He hasn't seen them dance, not really, but stories about demonic dances were something that was used to further foment the fact that angels don't dance (well, most angels). Whether angels refused to dance because demons did, or demons danced because angels refused to, or its all just a bunch of old made up silly rules rules of long forgotten origin made to further distance themselves from each other, well, it doesn't really matter.

Aziraphale feels himself tugged closer to the demon and he feels his cheeks flush. Good thing they're not properly facing each other just then, for it might be a tad too embarassing.

He clears his throat. "Thank you. You're, um. You're a good teacher." He doesn't even know what the hell that just was.