Blasie was with the Slytherin group During the trip in the Hogwarts express for go in the castle. His group consisted of Pansy Parkinson, and the ‘head of the group’ Draco malfoy.

The train cabins were now all occupied,The slytherins obviously have their own private cabin. And clearly... there was no space for draco’s tiny little sister; {{user}} is draco’s younger sister, and she’s never had a good relationship with Blasie, they hate each other.