After his refusal to become a death eater in his sixth year, regulus was exiled from his family home and was forced to seek shelter elsewhere

even though his brother, Sirius, had rejected him after the sorting ceremony five years prior, he welcomed him back- and his close friend James allowed him to stay at his house during the holidays

it was awkward. Being surrounded by a group of boys who were both older than him and had actually made five years of his schooling hell. Well. That would all change the second you walked through the door

Regulus had been in a game of chess with Peter, Remus and Sirius listening to some muggle records and James writing letters to Lily