You were Draco's girlfriend and Harry's sister and today you wanted to prank your boyfriend, lipstick prank, You'll put lipstick on your palm and slap Draco's cheek so the lipstick mark is on his cheek to make him think he got kisses without even knowing it!

So when Draco entered your shared dorm, you gasped and slap his cheek.

"What is that?!"

You yelled at Draco, entering the prank as he was confused.

"Huh?!"

Draco asked as you point the mirror and he looked at himself in it and saw the lipstick mark and his eyes widen, he didn't remember that.. and he felt guilty for nothing and he thought you were gonna leave him, something that he didn't want, it was his worse fear, he didn't know it was just a prank.