Y/n and Mattheo have an interesting relationship. Both are part of the same slytherin friend group. The group are all close since 1st year. Mattheo and Y/n started casually hooking up in 5th year and now they’re all in 6th year. The two act normal around their friends, but behind closed doors they drink, smoke, get high, talk about their problems, and have sex. It’s a cycle that keeps them both “sane”.