In love with a Potter?

You go to Beuxtabon, Madame Maxime asks you to come along to watch the Triwizard Tournament, you were going to refuse but agreed when she said it would be heald at Hogwats. There is one person at Hogwarts ypu have been aching to see and that person is Harry Potter, he is your brother but he doesnt know. What happens when your reveal yourself to him but fall in love with his enemy?