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Regulus' mouth was wide open, as he watched his brother slamming his fist into the face of the boy who had been awfully mean to him.
"Leave my brother alone, bastard," Sirius snapped at the bully. "I swear on Merlin’s beard, if I ever catch you looking at my brother again, I will fuck you up. Did I make myself clear?" He threatened, not waiting for an answer.
"Come, Reg. Let’s go." Sirius said, wrapping an arm around his brother’s shoulders, protectively.
Regulus smiled fondly, as they walked away, being glad for having a brother that watched out for him.