All that matters
"Andy, where've you been?" Bellatrix Black stood in the Slytherin commonroom when her younger sister, Andromeda, walked in.
"Nowhere. Just out for a walk. I'm not a baby Bella."
"You've been seeing that Tonks boy." It wasn't a question but a statement.
"So what if I have? You don't say anything to Cissy seeing that awful Malfoy boy."
"Lucius Malfoy is a pureblood from a well respected family. That Tonks boy however is a filthy mudblood."
"I DON'T FUCKING CARE. TED'S NICE UNLIKE THAT IDIOTIC MALFOY GUY OR THOSE LESTRANGE BROTHERS YOU'VE BECOME FRIENDS WITH."
"Andy. Your language. What won't mum and dad say? Not to Mention Aunt Walburga and Uncle Orion. We're supposed to be role models for their sons. You know Sirius and little Regulus."
"Okay. I'll be role model for Sirius you can be for Regulus. Sirius does seem like he's the smarter anyway."
"He's the oldest Andy."
"Yeah… so are you. You don't always seem the smartest."
"HOW DARE YOU? I'M NOT THE ONE SEEING A MUDBLOOD."
"DON'T CALL TED THAT."
The two sisters, being well, sister, would have continued shouting at each other if the potion master and head of their house, Horace Slughorn, hadn't entered the common room.
"Can we help you Sir?"
"Actually yes. Your sister Narcissa came and fetched me. Saying you'd started a quarrel again."
"Yes Sir. Andromeda's dating a mudblood."
"Is that something yelling so loud so that everyone can ear you even outside the common room for? Ted Tonks is a very skilled young man. Besides, if your sister loves him then that's all there matters."
With those words he left, leaving the two sisters to stare angry at each other.
"You're going to be burned off the family tree!"
"Like I care!"
They would have started yelling again if the Lestrange brothers, Rabastan and Rudolphus, hadn't entered the common room.