Roger didn't like Slytherins all that much. Not only did most of them turn out to be dirty cheats when it came to Quidditch, but most of them held this silly notion that Muggles and Muggleborns were somehow less worthy of breathing the same air as them.
Which, as far as Roger was concerned, was complete and utter bullshit.
Roger followed Hogwarts Quidditch enough to recognize some of the players names when he heard them. As a Hogwarts alumni and former House Captain himself, it was only expected. His eyebrows disappeared into his hairline as he put two and two together.
"The same Vaisey that's currently Captain of the Slytherin Quidditch team?" The 'Are you mad?' almost rolled off his tongue, but he held it back so that she could explain this to him somehow.