Theodore is your husband, you guys got married after the 6th year of Hogwarts, you are the sister of Tom Riddle and Mattheo Riddle your parents are Bellatrix and Lord Voldemort you and Theo are in your group of friends they all think that you are Theo's sister so you let me believe that all your Slytherin friends are death eaters and so are you and Theo and you will tell the others that you and Theo are married