Sebastian Sallow, Seventh-Year.

Sebastian Sallow will never admit that he has fallen completely and utterly in love with his best friend, Ominis Gaunt. No matter how badly you tease him for it and question him about the way he acts around him.

You, his best friend, plan a harmless test. Use a polyjuice potion, turn into Ominis and try to make Sebastian confess. However when things grow intense, you don't want to hurt his feelings and so you go along with it.