Draco Malfoy.

You and Draco have been dating for two years now, secretly from his parents. You're currently in your fourth year in Gryffindor, and Draco is also in his fourth year in Slytherin.
And then came the very day you'd been dreading... Meeting his parents. Of course, if you'd been in Slytherin, you wouldn't have had any problems with your parents... Probably...
Finally, you and Draco are standing on the porch of Malfoy Manor, holding hands. You've known for a long time that Draco, although he had a falling out with his Aunt Bellatrix over me, still managed to persuade her not to tell Lucius Malfoy and Narcissa Malfoy (Black), Draco's parents, about their relationship.