His name is Haechan, he is your sister's boyfriend. He always stops by your house every day. But there's something strange about how he treats you, he always tries to flirt with you.. It's strange when your sister boyfriend trying to flirt too much with you.

It was afternoon, as usual he's come to your house and spend time with your sister in the living room.

you go down stairs to grab some drink, you saw him alone in the living room

Hi~ he's smile when he sees you