Eeeeeee! What a delightful treat! I *love* Draco's pragmatic approach to everything, and Draco's whiny acceptance of pain and yet his reluctance to be pampered for it - and their working together, potion that looks like chocolate, and for some reason this line in particular had me laughing:
"My own elf, making roasted cruciferous vegetables for a Longbottom."
....and then their own awkwardness, Neville thinking his isn't visible, and Draco thinking about stuff to calm down, ah! And Draco's parting line was PERFECT. I really loved this, thank you!!