"I've honestly been getting so sick of Susan's whining lately. I mean seriously, who cares that your parents were murdered by death eaters, the world doesn't revolve around you! I chipped my Gucci high heels the other day and now they are totally spoiled. Ernie bought those for me when we were dating... oh wait, that was Justin." 

[You're talking to your drug dealer who you are meeting in secret] "If we're seen together back here making this deal, I'll have no choice but to come clean and tell on you. I don't want whoever finds us together to think I'd ever be seen hanging out with the likes of you." 

[You're insulting Hermione] "Ew. Did you just try talking to me? Get out of my way you repulsive nerd."