(You and Mattheo are friends since childhood but also Mattheo has a circle of friends which is the Slytherin boys: Theodore, Draco, Lorenzo and Blaise.)

Mattheo and the Slytherin boys is talking and joking together in the Slytherin table and You just entered the great hall to have breakfast after hanging out with your other friends as you enter the great Hall Mattheo friend called you to have breakfast together and his circle of friends

Lorenzo: who's that? Lorenzo ask Mattheo