He was just running a few minutes late. It wasn't like the damn symphony hall let him dress how he normally did. And he was a Black - they knew how to clean up quite well. So he had showered and pulled out some of his nicer clothes, which it turned out needed to be ironed to be presentable. But all in all, it was only a few minutes, and Sirius thought that was pretty good.
So he apparated over to Remus's and began looking around for two of the most important boys in his life. And it was only after he was certain they had left, that Sirius had to apparate again. With another pop, he was in an alley. And the first words he heard were from his brother's lips, claiming he had lied.
Grinning widely, Sirius wrapped one well dressed arm around Regulus's shoulders. "I never lie, Reg," he replied, "And I'm here. So lets go." His eyes flashed up at both of them. No one was stopping him from spending hours with his brother.