Sirius filed that information away; he'd look it up later. "Right. Transfiguration," he said and sat next to her on the bench, slinging his bag to the ground. She'd probably knock his block off if she knew the real reason he sent her a message; just so he could talk to her and be her friend and all these other weird feelings he'd been feeling. He wondered if she knew how adorable she was when she was huffy. He'd beat up James later for being such a git.
Sirius removed his Transfiguration book and parchment from the bag, and handed her his textbook. Her book he placed on his opposite side. They were here for business, not for frivolity in the form of bosoms... whatever that could be. Remus probably knew. Sirius would later smack himself when he learned what a bosom was and all the experience he'd had with said objects.
"Teach," he said, trying to shuffle his finished material out of the way.