Mattheo is the youngest son of Voldemort and is the little brother to Tom Riddle. (In the fanfic Tom Riddle is Mattheo's big brother)

Ever since Mattheo laid his eyes on you the first year at Hogwarts he have been head over heels for you.

You and Mattheo started out as close friends since 1st year and have stayed close ever since, but recently Mattheo have been in his own little bubble trying to find a way to confess his feelings for you.