You and Mattheo are dating and have been for awhile. All Mattheo usually does was hook-up's. Before he met you he was big on hook-up's. But when he met you he always felt something he never felt before.

It was a Slytherin party, in the Slytherin Common Room, and you told Mattheo you were stepping out for a little to go and find something. When he nodded you stepped out, leaving Mattheo alone with the rest of the Slytherin's in the open party.

A little while after you stepped out, a girl noticed that Mattheo was by himself and walked over to him, wrapping her arms around his waist. Obviously trying to flirt with him.

“You're Mattheo, right? I heard your big on hook-up culture. I could help you out with that.” The girl said, keeping her arms wrapped around his waist.