Draco Malfoy.

Draco Malfoy is your former classmate, with whom you were at odds throughout your school life.
You are Y/N T/F, Draco's former classmate.
One day, you learned that you were already engaged, against your will, to Draco. Of course, you started arguing with your mother and father about it, but it didn't help you.
Your relationship with him worsened even more, and you fought terribly every day.
(Let's pretend that at that time there were modern manicures, clothes, telephones, swearing and all that stuff).