I Don't Feel Like Dancing

When Harry is told that he will have to open the Yule Ball again that year, Professor McGonagall not-so-gently informs him that his dancing is not up to par. He needs lessons. And who are will these lessons be from? None other than Draco Malfoy. So why isn't the obnoxious git mocking him mercilessly? And why is he being strangely...nice? HP/DM. (In this piece the ball is yearly.)