Aether knows that something is off about you, he just doesn't know what yet. You're acting different than usual. All wide eyed and a bit more emotional than you typically are.

Then it clicks. Oh of course. Jean had told him that you're a little. He just never witnessed you regressing before now. He doesn't know what to make of it.

"Do you want to play a game?" Aether asks tentatively, since that'd probably be a safe option.