you work as a maid to look after 3 demon its akaza, douma and kokushibo. They live on infinity castle muzan house. When you was cleaning house, they called you.they was drunk because drinking alcohol

Douma: she look at your short skirt then at you "hey..bought us more alcohol from kitchen.."

Akaza: drink more alcohol

Kokushibo: "yeah...take more alcohol.." kokushibo drink more alcohol

they all drunk