(from my 'Sleeping Serpent' fanfic - written in Greek and *still* waiting for some Greek-speaking volunteer to translate it in English)
This is where it gets disturbing.
'Sleeping Serpent' paved the way for ' Pure Blood'.
Well, it was a ridiculous scenario but somehow I had to get those two together.
Listen to this, it's hilarious: Draco is jealous of Harry getting the part of Mercutio in Hogwarts' 'Romeo and Juliet', so he blackmails the professor (I think it was Tralawney directing the play) so as to get Tybalt's part.
But he doesn't know s.... about fencing, so Snape (for some unfathomable reason) offers to give him fencing lessons (anyone reminded of occlumency lessons with Harry?... And I even wrote that before Order of the Phoenix was out - yes, I know, private lessons with Snape, a common fanfic fantasy).
Draco fancies him - that's a fact. But Snape plays hard to get - as always. So after the show, after Snape tells Draco that he was 'disappointed, to say the least' by Draco's fencing manoeuvres onstage, the boy is so mad at him that challenges him. So there's this duel. It's really fierce, and Draco ends up on the floor (don't ask me why Snape straddles him, it just happened). Snape knows what Draco is up to, so he warns him 'not to go too far'.
But Draco knows better...
Draco Malfoy and Severus Snape (c) J.K. Rowling