This oneshot is taking place in a AU where Severus Snape didn't let the influence of the other death eaters get in his brain and is still friends with Lily. He is in mutual terms with the marauders here.
(The Gryffindor Common Room)
"Oh no, not that expression. Sirius what are you up to?" The young 7th year gryffindor werewolf asked his friend.
"Yeah Padfoot, what is it? Do you have some idea for a prank?" The stag animagus questioned.
"Huh? What do you mean Moony?" The dog animagus asked with a very innocent facade.
"Comon Siri, you're a terrible liar. You never hide anything from us, what is it?" James asked.
"Well, with all honesty I was thinking about how to annoy my parents now that I am disowned." Sirius replied.
"Really now, you want to annoy them even more? One would have thought being sorted to Gryffindor would've been enough." Remus commented.
"Oh please, they're my parents. I will die if I don't cause them to rip their hair out every week. And I haven't caused them any trouble since sooooo long." Sirius commented.
"You are unbelievable." Remus rolled his eyes.
"Well it's nit like we can vandalise the Grimmauld Place. The only person who have the access to that place is your brother and some other Slytherins." James spoke.
Suddenly Sirius' face lit up, "Guys, I have the perfect idea. Jamie where's your girl?"
"Uh, probably in the library, why?" James asked confused.
"I need her help."
"Lily! Lily!" Sirius practically rushed towards the pretty red head the moment she entered the common room.
"Woah woah, slow down Sirius, what is it?" Lily asked calmly.
"I need your help to talk to Snape and my brother. Can you ask them to come at the Shrieking Shack today at 6?" He asked.
"Um sure?"
(The Slytherin Common Room)
"And now you wave your wand over potion in a figure of eight and say incantation 'Felixempra'!" A tall half blood 7 year Slytherin instructed.
"Thanks Severus, I don't know how is get my O's in potions without you." The 6 year pure-blood thanked.
"No problem Regulas, though I don't understand why you don't ask anyone your years for help. I am sure they'd love to help the next Black heir." Severus Snape questioned.
"Well for one, do they even know what they're doing? And you explain stuff really good too. And they're friends with me just because I am a Black." Regulas replied.
"Understandable."
Suddenly a great grey owl flew inside the Slytherin Common Room with a letter and sat on Severus' shoulder.
Severus gave the majestic bird a treat and started to read the letter.
"Evans'?"
"Mmhm." Severus nodded, before commenting, "Weird."
"What's weird? Did she broke off with Potter and now wants to date you?" Regulas questioned.
"Of course not, plus I am over that now. To think of it, our relationship is more like siblings then lover. No, your brother is asking to meet both of us at six at the Shrieking Shack today." Severus asked with shock and confusion, so much so that he didn't even roll his eyes at Regulas' comment.
"After all this time he wants to actually meet me?" Regulas asked, even more confused and shocked than his friend.
"I mean, I guess we'll figure out what's going on in that chaotic mind of your brother at 6."
(The Shrieking Shack)
"Prongs?" Sirius called out.
"Here!" James exclaimed enthusiastically.
"Moony?"
"Here." Remus replied casually.
"Wormtail?"
"Here!" Peter squeaked.
"Red head with a temper?"
"Here." Lily replied with an eye roll.
"Snakey Snapey?"
"We're all here, just get to the bloody point!" Severus replied annoyed.
"Sevvy baby?" Sirius asked as of ignoring what Snape had just said while James snickered at the nickname.
"Here." Severus replied with a annoyed sigh.
"Lego Reggo?"
"Here?" Regulas called out, still confused as to why he's here.
"The most handsome man alive? Oh wait, that's just me. Very well. Good morning everyone-"
"Evening."
"Yeah yeah, whatever you say Moony. Today we are here to discuss a very very important topic." Sirius started to speak.
"And why am I here?" Regulas asked.
"I am getting to point, chillax. Anyone first let me ask you, who over here hates my parents?" Sirius asked and surprisingly to the gryffindors, both the Slytherin s held their hands up with them.
"Wait you two hate them?" Remus asked confused.
"Of course I do, ever since Sirius got sorted to Gryffindor mom and dad have been trying to make me everyone Sirius isn't. I don't want to be straight and marry some random bimbo." Regulas spoke.
"You're gay?" Sirius questioned.
"No, I am aesexual. I hate myself but still think that I am too good for anyone." Regulas replied.
"And ever since Walburga Black became okay with my half blood origins, she's been planning to get me to marry a proper woman and not repeat the mistake of my mother." Severus replied.
"Wait a second, your a half blood?!" The Slytherins exclaimed.
"Is that all you got from that?" Severus asked raising his brow.
"Uh well moving on. Since we all hate my parents, I came up with this brilliant plan to annoy them even after death. I need y'all to sign this contract so that when you die, your blood will be used to write fuck you on the walls of the Grimmauld Place. I've already got Ciara, Alexis and Dominic from Ravenclaws and Sarah, Aminos, Jia and Kevin from Hufflepuffs to agree. And since the heir of that place is Regulas, you are here." Sirius exclaimed.
"Thats-" Remus started to speak
"Bloody brilliant!" James exclaimed.
"Sign me up, can't wait." Regulas replied.
"Ooh! Ooh! I dibs on your parents bedroom!" James exclaimed.
"I dibs on your mum's jewellery!" Lily exclaimed.
"Can my dibs be on your father's study?" Peter asked.
"Mine are your mom's fanciest of disastrous dresses." Severus spoke.
"I want dibs on mom and dad's favorite family portrait." Regulas spoke.
"Oh hell on that's mine! You pick something else." Sirius exclaimed.
"I went through 16 years of torture with them and still am, I deserve it more!" Regulas retorted.
"I was born first!"
"And you'll die first too!"
And then for hours the two Black brothers kept on arguing for the first time in years as their friends just looked at eachother nervously.