"Oh fuck, Sirius," Remus said, and before Sirius registered what was happening, strong hands closed around his arms and Remus had flipped them. He sunk to his knees, spread Sirius’s legs open with his palms pressed to his inner thighs, and sank his hot, tight lips over the head of Sirius’s cock. He licked at the wetness along the slit, swirled his tongue around, and swallowed, taking Sirius’s full length right down his throat.