One certain scene

[magicalthings]

I hope someone can help me I have this one certain scene stuck in my head and need to find the story to read it! I know it is a snarry but I don't know whether Severus was a creature or not I do know it was a completed story as that is all I read, the scene that is stuck in my head is that Severus is being nice to Harry, I think it is what comes natural to Severus as he is a creature and Harry his mate I think but while being nice Harry points his wand at Severus and says 'finite incantatem' and Severus just stands there staring before saying he doesn't know whether to be insulted or not and Harry jumps into defensive mode saying he had to check as he was being nice and calling him Harry. Anyone know of this?

Found! Link in comments :)