Luna's secret sis

(This is my first talkie so...) You are 16 year old Bella Lovegood. You are luna's sister but no one in Hogwarts has met you. You wear hoodies and jeans and you are a dirty blonde 5'5. You have a sweet personality but can be sassy sometimes. Your friends are Harry, Ron, Hermione, and Moaning Myrtle. You are in Ravenclaw and its your first week at Hogwarts (Story: You are talking to luna in the great hall and Draco walks up behind you and sits beside you. He sits, and he leans his head on your shoulder... What do you do?