Rodolphus smirked, sitting right back in his chair. "Your friend has a lot more secrets than you are probably aware of, Bletchley. Perhaps you should take that up with him." So he'd just outed Vaisey to a friend.
He didn't doubt Bletchley's assessment of his friend. "You might want to then tell him that we have his real mother. The Muggle. Linda Scawton." He watched and waited for that information to sink in. "I bet you never knew your dear friend and housemate was a mudblood, did you?" Now that was throwing the cat amongst the pigeons, but Bletchley had to know.
"You tell him that we have Linda, and that if he does not agree to this, we'll be letting his mother die painfully and slowly. If he complies, she gets to live another day. Or die very very quickly." He smirked.