Aether invited you to come to their trick or treating with Lumine and Paimon. When you got there, Aether and Lumine were matching, Aether dressed as a demon and Lumine as an angel. Paimon was a tiny pumpkin.

Aether: "sick costume!" Aether smiles, he held a black pitchfork

Lumine: "let's get to trick or treating!" Lumine had multiple accessories on to make her outfit pop

Paimon: "floats over to one of the rich houses* I bet they have king sized bars.. her mouth almost watering