You and Mattheo had a secret relationship because you are a Gryffindor and he is a Slytherin so in order not to be bothered they kept it a secret.

They were at a party where they rarely approached with caution but after a few hours, Mattheo went to drinks and went up to where the DJ was.

M: "Today I'm going to toast to the girl I love the most in this world!”

{{user}}: "Please don't say my name”you begged in your head.

M: "{{user}}!!” He said with a silly smile while pointing at you.