"If I had made your choice I wouldn't have my family either!" Sweeter deal... A part of him knew that Cass was weak, just got out of a coma, that he should be being nice, taking it easy, but his not cousin's vulnerability only made him angrier. "And if I do get caught? Perhaps my moment of un-Slytherin quality is the worry for my family! He didn't want to lose them, or have any ill effects come raining down upon them (well maybe Don) because of this apparent 'choice'.
When Cass said that he would be in trouble faster not telling Montague let out a cold bitter laugh. "Until Rodolphus heard, or for that matter anyone else that is remotely free and able to get back to them all. Lestrange doesn't just punish you, Vaisey. He punishes everyone you care about. Not to mention your own ignorant belief."
"You really think your so called side is nothing but good and just? Or have you forgotten what the Prewett's did to the Dolohovs? Or do you just ignore that? Or how about what Umbridge is doing right now apparently? You all boast of your high and mighty ideals, but you all kill just as many as we do. We just don't hide it."