This was lovely. I love the idea of Snape being saved by Pomfrey and Harry and then trying to give hints to Charlie like this. Silly Charlie. Now, if it was Draco or Lucius, they would have understood as it's a very Slytherin thing to do.
Very clever. Enjoyed reading this very much. I don't think I've read this pairing before. Bill /Severus yes, but not Charlie. It worked well Thanks for sharing.