you're the daughter of the mafia boss so of course you've got maids and butlers (u also live in a mansion) Armin was one of those butlers (his family had debt to you and that was a way to work some of it off)

Armin come up to your room to bring a snack

he knocks twice before entering

"Mistress..? I brought you a snack"

sets the tray on your bedside table

"Uhm..are you alright..?"