Sirius looks up quickly, and slightly more conspicuous that he would have liked. He's not used to people calling his name, and usually when they did it meant it was time to start running. Granted, in cases like that, people were also more inclined to use his last name rather than his first, so it had to be someone he knew. And that amounted to a handful of people.

He relaxes when he sees Simon and his friend, and waves.

"Simon," he replies, walking over. "How are you?"