You know what you've clicked into

Sirius always joked about putting a dress to his own wedding, but didn't because Remus begged him not to.

Sirius was once worrying about his outfit to Remus' and his date. James told him casually "I think he would like it best with out any clothes at all, but maybe he is into stripping them off you, so put something on just in case." It was the first time James made Sirius blush.

Sirius and Regulus didn't cry when feeling pain as they were used to it from their past. Only if it came by full surprise they would yelp or smt

Regulus was good at lying, but Sirius and James always noticed even if no-one else did

Sirius and James neither really hated Slytherins. They thought it would impress the other, so they did it. Only Slytherin they actually hated, was Snape

Regulus and Severus didn't get well together, because Regulus thought others before himself and always wanted to make others happy and pleased, but Severus thought of himself and only the people very close to him.

Regulus loved to read romance

Lily was extremely interested of magic history, because she was a muggle born

Regulus and Sirius were taught how to play the piano and dance before they had even started school, because their parents wanted them to have fancy hobbies. They were also thought how to eat nicely and how talk like a royalty. Basically they were taught how to be a royalty

Remus bought Sirius an electric quitar as an birthday gift one day, because he didn't know what Sirius wanted (as this was only their first year). Sirius didn't know what it was at first, but when he learned to use it, he loved it.

The Marauders did a lot of pranks, but they enever went as far as hurting anyone. The only time was when Sirius told Severus-.... We don't talk about it

After the Halloween (you ain't a potterhead if you don't know what i'm talking about) Remus fell into a deep depression and tried to commit a suicide mutiple times, but failed and decided to give up

Remus is Bi 100%

During the time Remus was a teacher at Hogwarts, he never admitted of having a favourite student, because he wanted to be fair toward everyone. However, it was definently Harry, because he reminded Remus so much of James. Ron was second, because he was like Peter in Remus' opinion; loved food and played chess.

Remus and Severus glared each other at every possible situation during the teaching year.

Remus loved to tease Severus about how he, a werewolf, a broke and a Bi sexual, got the job Severus wanted

Y'all remember that scene when Remus found out Harry had the map? Well Remus had to hold back tears when he saw the map say mr. Wormtail, mr. Moony, mr. Padfoot and mr. Prongs present, THE MARAUDERS MAP

There ya go, another 500 words of headcannons