Sirius cautiously nodded his agreement, because he really didn't want to keep a wonky arm forever, it was true. He averted his eyes as Remus rolled up his robe and shirt sleeves, because if he didn't want to look when it was all covered up, it was going to be much worse when it wasn't. Instead he looked over at Philip. At least there wasn't going to be trouble. Philip was good to have avoided that. If it were Phinny he'd have been running to tell all the adults exactly what Sirius had done. Sometimes Sirius missed his little brother, but not today.
He tried to focus on Remus' words. Magic, of course it was magic, Uncle Arcturus said the muggle doctors did horrible things. But why was Mr Lupin here and not Mr O'Hara? Mr O'Hara had potions, they all knew that. Then Mr Lupin said it might hurt, and Sirius turned his head towards Arcturus instead, because he had to say no, didn't he?
He didn't. There wasn't any time. Sirius heard that horrible sound. The pain came a split second later, and he yelped in alarm, before looking at his uncle in dismay, as if he'd just suffered the very worst betrayal. Then his lower lip started wobbling again, because this was horrible, Mr Lupin moved his arm and it hurt and it crunched and the potion was no good and it was not fair at all.
'Sirius!' Arcturus waited until Remus' bandaging spell was finished before he stepped forward, but as soon as he knew he wouldn't be in the way, he was at the little boy's side. 'Siri, listen, it's over now. It's all over and you were so very brave. We all think so. Look, your arm is nice and safe now until we get the other potion brewed. How does it feel now?' It hadn't been pleasant to watch. Arcturus was glad he'd let Sirius have such a generous dose of his potion beforehand.
Being told that he was brave made Sirius try very hard not to cry again, and when his lip had stopped quivering he realised that while it had hurt when Mr Lupin did the spell, now it didn't. His arm was all bandaged up but it didn't look terrible like before. He gave another little nod. 'It is not bad,' he admitted. 'Mr Lupin, I think you are a good healer.'