"Bella! Why are you doing this?"
Bellatrix hissed. "How dare you call me that, Andromeda? I'm not "Bella", not me. I don't even know who you are anymore!"
Andromeda's eyes were filled with tears. "Of course you do, Bell! I'm your sister, I'm your best friend! We've always been best friends. Just last week you told me so! Bella, please!"
"Don't you dare call me that! And you know perfectly well why we can't be friends anymore! You're going and marrying a mug- you know, I don't even care. You're going and marrying that mudblood Hufflepuff. Why the hell would you do that to me? STOP CALLING ME BELLA RIGHT NOW! ONLY MY SISTERS CALL ME THAT YOU FILTHY LITTLE COCKROACH!"
Bellatrix was screaming at the top of her lungs, her face stony as she tried not to cry. Andromeda was crying, on her knees, pleading.
"Bellatrix, I am your sister! You love me. I love you. We asked mom to let us share a room when we were four. We've been best friends since the day we were born. I only wanted to play with you. We bought our wands together. We got our Hogwarts robes together. We sat together on the train that first year, and all the years after. When we were both sorted into Slytherin, we were so happy. We picked beds right next to each other. We sat next to each other in every class. We went to our first Hogsmeade trip together. We had our first Acid Pops together, and were in the Hospital wing for a night because of it. We cried together when Mummy and Daddy divorced. We had our first boyfriends at the same time, dumped them at the same time. We planted dungbombs under Regulus's and Sirius's chairs at Christmas. We've done everything together, Bella! Does't that mean anything to you?"
Andromeda's soft face was soaked with tears, her hair almost as frizzy as her sister's. Her hands and arms were shaking, her feet and legs immovable. She wanted her sister, her best friend, her twin to forgive her, allow her to love whomever she wanted.
Bellatrix's face was stony, hard, but silent tears were streaming down her cheeks. Her arms were crossed tightly, her legs stuff, her feet cemented to the floor.
"Those memories mean nothing to me. YOU mean nothing to me ever since you chose that filthy little mudblood over me."
"But does it have to be an either/or choice? Can't I have you both?" Andromeda sobbed.
"No."
At that one word, Andromeda began sobbing more than she ever had before. More than when she didn't get a cat for her birthday. More than when she broke up with her boyfriend. More than when her parents divorced.
"Bella-" Andromeda cried.
"You need to leave, Andromeda. You need to leave, now. Get out of my face and never speak to me again."
"Wha-What?"
"GET OUT OF HERE! RIGHT NOW! GET THE HELL OUT OF THIS HOUSE! YOU ARE NOT A BLACK, YOU NEVER WERE! GET OUT, NOW!" Bellatrix screamed with fury.
"Bella, please."
"NOW!"
Andromeda waved her wand, sobbing as all her possessions shrunk and flew into her small bag.
"Get out of this house. Don't come back. Never speak to me again. You are a disgrace, Andromeda. I can't believe you were ever my sister."
A small puddle of tears were left where Andromeda Disapparated.
Without another word, Bellatrix burst into tears.