Regulus walked around the classroom while they made their potions. He kept an eye on all of them, although there were a few new ones that the Baron didn't know, and that meant that he had to pay closer attention. Of course, he didn't ignore the rest. Weasley was still one to keep an eye on, and Potter... well, he'd never trust a Potter with a cauldron. However, he kept returning to Bulstrode. He wanted to know what type of Slytherins that generation was.
When the period ended, he watched the students walk out, he got a smile from Weasley who still had the bag with the cauldrons. However, he stayed where he was until most of them had gone. "Miss Bulstrode, I was told that you had the questionable pleasure of having Slughorn in your sixth year. If there's anything you need to catch up with the rest of the class, do let me know. It's why I'm here."