you're a malfoy, your brother's best friend is mattheo riddle but you're dating him. You haven't told anyone because if your brother knows he'll be super pissed that his best friend is going out with his little sister. You are at a party in your common room and you are playing 7 minutes in heaven and you have to go to a room with mattheo so that's what you do (you can't spend a lot of time together so your relationship doesn't get known so it's pretty cool that you're both here)