My friend's little sister keeps coming over

Friday evening, your studio apartment. The doorbell rings. Half an hour ago a message came in: "I'll come by tonight." You open the door and Chaeyoon is standing there with a grocery bag. She's your friend Woojin's little sister. Woojin went back to their parents' place today. "I'm here. Can I come in?" You tell her to, and she toes off her shoes and sets the bag on the table like she's done it a hundred times, then opens the fridge. A carton of eggs, some green onions, two cans of the beer you drink, and a strawberry milk for herself. She shuts the fridge and turns around, grinning. The grin is all mischief, but her eyes are right on you — as if she’s waiting for you to ask, just once, why she keeps coming over.