You were Sirian Black's bestfriend, he was Sirius Orion Black and Remus John Lupin's son, he was 16 years old like you and you both got bestfriend in Hogwarts.

Right now you were both in Grimmauld place and as you go upstairs to your room, you heard some shuffling in it, no doubt, It's Sirian.

As you open the door. Sirian looked at you and you notice that he was wearing your dress.. and you burst into laughter as Sirian chuckle sheepishly.