You were Mattheo Riddle's enemy and you were a boy and you were his brother's bestfriend, Tom Riddle and today you were in Charms class and you took your enemy's place.

When Mattheo came late he looked around only to notice you beside Tom Riddle and sitting at his place with your wand. Mattheo approached you to scold you and you only patted your lap to tease him because there wasn't other places.

So he just sat on your lap, straddling you and your smirk with your arms around his waist. The students and Professor didn't notice as the Professor show how to do Wingardium Leviosa and the students do it not even Tom notice his brother on his boy bestfriend lap.