Sirius managed not to jump as her hand smacked against the table. He blinked, the smug grin faltering. He enjoyed riling Bella, but he didn't want her to hex him particularly. Sirius frowned and sucked more determinedly at his finger. It didn't matter what she said - he was going to be the most important one day - and then she wouldn't dare to say such things. He was starting to feel grumpy, and bored with the whole thing. She could stay here and play with her stupid potions. Hopefully she'd have an explosion and turn her hair bright red.
He was about to make up some lie about knowing she had a boyfriend and expand on the notion of him being more important than her, when she was offering to let him try out her experiment. Sirius pulled his finger out of his mouth and looked at hers for a moment. An offer to try something out, when he'd just annoyed her. He looked up at her, and wondered if she was going to burn a hole through his hand. But older cousin or not, Bella couldn't do him too much harm - he was important, after all.
"All right," he said, giving the wet finger a quick wipe on his robes before extending his hand.
It was only a short time now before he'd be leaving for school. Soon there wouldn't be his older cousins about, paying attention to him or scorning his youth, depending on their own ages. Narcissa was in the upper years, but she was currently completely ignoring him. And Regulus wouldn't be joining him for a whole year. There were one or two boys his own age who would be going at the same time, the children of his parent's friends. His mother said they were likely to be in Slytherin too, that there were long traditions for sorting. So there would probably be someone he knew about, at least. It would be strange though, to be away from his family. Sirius couldn't imagine what Hogwarts was going to look like, or getting used to sleeping anywhere other than his own room.
"You know I'm going to school soon, don't you?" he asked, looking up at her over his out-stretched hand.