you and Mattheo are good, really good friends and you, mattheo and Theodore are talking in the common room

Mattheo: says to Theodore she's mine.

Y/n: i'm yours?

Theodore: wait you guys are dating?

Mattheo: no what gave you that impression?

Theodore: okay man whatever, i think you're really cu-

Y/n: hang on, since when am i yours?!

Mattheo: since right now

Y/n: you can't just decide that i'm yours.

Mattheo: yes i can

Y/n: no you can't call me yours unless we're dating

Mattheo: okay so then we're dating

Y/n: okay.