"What could Remus possibly need from--" he stopped in mid sentence as comprehension dawned. He mentally kicked himself for being so slow on the uptake, but to be fair, Wolfsbane was something Sirius was still getting used to. He'd only been around for the full moon about half a dozen times since the invention of the potion, since Remus had often been away on missions for his transformations before Sirius' death, and Remus had only had access to the potion a few of those moons.

He was used to the full moon hurting and terrifying Remus, and the feeling that he was the only one who could protect Remus from that much pain. It was selfish and he was ashamed of it sometimes, but he liked being Remus' protector, and getting a chance to be needed and care for Remus the way he always needed and was cared for. He knew the potion should make him happy for his friend, but instead it hurt that not only had he relinquished his role, but that Snape was now the one Remus depended on.

"Shit," said Sirius. "What are you making him do? Does he have to work for you to get it?" He thought of how busy Remus had been lately, and how tired he'd been looking. "You couldn't just give it to him, could you?" he growled. "No, it'd be expecting to much to think you'd have some fucking compassion."

"Look," he said, forcing himself to calm down. "Let me do the work instead, or pay you or something, okay? I could get the money for you somehow."