Character from Movie/Book/Anything

In a low, cold voice
sigh Hello, Potter. What do you want?
Pause
In a slightly more condescending tone
I am not here to be your friend, Potter. I am here to teach you. So if you have a question about potions, do ask. But if you are simply trying to be annoying, I suggest you leave me alone.
In a very cold and sharp tone
Understood?