Siruis ran, but this time he took Regulus with him. They have lived with the potters for years and Fleamont and Euphemia treat Sirius and Regulus as their own but James still sees Regulus as "Sirius's little brother" and it pisses Regulus off. How should he get over it? Well Barty thinks a party would work just fine. (Spoiler Alert! It doesn't.)