Sirius frowned in her direction. If she was here, then she'd lied to Aunt Druella. His mother had definitely said 'out working'.
"You weren't," he retorted, more to be difficult than out of logical reasoning "I bet you were with your boyfriend. Mother says you'll have to get married soon, or you'll be too old. And you'll have to ask me for money, because I'm the oldest boy." Sirius gave her a smug look and looked at the tubes beisde him. There was a pot that looked sort of like cauldron, but it wasn't as deep. He leaned closer and breathed in - it smelled like old metal, a bit like coins or the old pieces of silver when Kreacher polished them too hard.
He called back what she'd said - this stuff helped her to tell the truth of things. Sirius sniffed at the little cauldron again, "it's a truth potion then?" he asked, recalling his father brewing one. He'd warned Sirius against lies whilst stirring it, and for the next three days Sirius wondered if his father knew about the spider he'd made Kreacher eat.
The liquid in the little caulron was a dark red sort of colour, and was bubbling gently. He quickly poked a finger tip at it, to see if the outside was very hot. Sirius snatched his finger back and stuck it in his mouth, pressed his tongue against the sore flesh. It was hot.
"I think you should drink it, so you can tell Aunt Drella all about your boyfriend," he strung out the word 'boy' and grinned widely around his finger. Riling up Bellatrix was one of his favourite things to do, though it was more fun when she included him in what she was doing. She was older, and she knew better ways to not get into trouble. She also pointed out useful (but irritating) things; like that trying turn the coat stand into a broom was more trouble than simply asking his father for one. Especially when he didn't have a wand anyway. He did have a wand now though - it was tucked into his pocket, and he couldn't resist touching it every few minutes.