An angsty nothing that came from goodness knows where. No beta and no second guessing, so forgive me.
The first kiss was Sirius's fault. Remus was trying to finish that blasted Charms essay that wouldn't end and the other boys were drunk and just far too loud for Remus to properly concentrate. He tried to herd them out of the dorm, but only succeeded in helping James slip down the stairs. Laughing and shushing no one in particular, Peter wobbled his way over to James to help him finish the stairs to the common room. And then Sirius was laughing, pretending to hide from Remus behind the dorm door that he'd managed to shut. Remus tried to pull him away from the wall, but Sirius giggled and grabbed Remus. His hands gripped Remus's forearms and Sirius pressed them together and pushed his lips to his friend's. Remus stayed frozen, even after Sirius pushed away, coughing and laughing nervously. Even after the door was open and shut and Remus was alone in the room, he stood silently for a long moment—tasting whiskey and feeling altogether too warm with a knot in his stomach.
The second kiss was Sirius's fault too. It was 7th year and James had finally gotten Lily Evans to pay attention. Sitting around the fireplace in the common room, the Marauders were plotting ways to bother Snape. James suggested that they go easy on him, as it was Christmas next week. Lily cooed and called James a complete sweetheart. Blushing, James leaned in for the expected kiss, despite the laughter of his friends. From his lounging position on the sofa, Sirius rolled his eyes and announced that he could get a sweet girl to play house with him just as easily as James did. He declared he could do it right now too. Sirius tugged forcefully on Remus's jumper until only Remus's arms automatically bracing on either side of Sirius's head prevented Remus from landing on his friend. Leaning up, Sirius caught Remus in a rough, open-mouth kiss that left everyone laughing but left Remus hard and panting every night after.
The third kiss was only sort of Sirius's fault. Mrs. Black had died and although he was out of the will and off the family tree, it was deemed socially necessary to Sirius to attend his mother's funeral. Lily and Remus came along as moral support for a Sirius overwhelmed with hate and grief clashing in a sea of confusion. Humiliating Lily, the very bitter Sirius made sure his family knew he'd brought not only a Muggle friend, but one who was marrying a pureblood and thus weakening the bloodlines. But to seal the deal of a familial exile and disastrous final reunion, Sirius announced as the three were leaving that seeing dead bodies always made him so hot and proceeded to push Remus into the wall and his tongue into Remus's mouth. When an hour later they were seated in a bar, well past their first pint, Sirius distractedly confessed he'd never hated himself more than when he remembered who and where he came from. Lily and Remus exchanged a glance and knew they both would forgive Sirius for what he'd done, but Remus knew that he didn't want to forget.
The fourth kiss was Remus's fault. It was a cold October and everyone was afraid for the Potters. There was too much tension, not enough trust. Remus was pacing back and forth across the floor of the abandoned farmhouse where he was going to transform any minute. Peter had plans and James had a son so Sirius was the only other one there this month. Remus couldn't calm himself, even when Sirius pointed out this was just like every other month. Because the fact was things were different, and Remus felt a lump in his throat as he tried to explain. Everyone they'd ever loved was hanging precariously on the edge. Emboldened by what, he didn't know, but when Sirius said Lily and James and Harry would be fine, Remus bravely shouted they weren't the only ones he loved. And he kissed Sirius. It was short and Remus couldn't be sure if it had even been reciprocated. As he fought back tears and every fear in his mind Remus whispered against Sirius's lips that he wanted Sirius safe, because he always wanted Sirius to be there every night and every morning. And that night Sirius was there when Remus rapidly transformed moments later, but when he awoke in the morning Remus was completely alone.