A/N: I have a lot of feelings about these two. Enjoy, and please leave a review if you liked it!
First Kisses
The first time they kissed, it was flustered and rushed and passionate in a way that could only be described as animalistic. It was about the sex really, neither of them denied it. The kisses were harsh and border lining painful, but it was glorious in ways that they never thought was possible. It was the kind of night that made it hard to walk the next morning, and Lily was worried about the nasty bruises all over Remus' body for the following week, although she never understood what they really were. It was that first kiss that lingered on them for days and caused Sirius to have a certain indescribable look in his eyes whenever their gazes tore across each other. They managed to practice self-control for twelve hours before they were at each other again in a broom closet on the fourth floor.
The first time Remus kissed him with meaning was during a bitter winter day. They were wandering the grounds, looking for James and Lily, but not really wanting to find them because it would disturb the silence. Sirius wouldn't stop muttering about his toes freezing off and Remus couldn't stop smiling. They stopped at the edge of the lake so that Sirius could re-wrap his scarf more tightly around his neck. Remus had insisted on helping since Sirius' thick gloves made grabbing anything impossible. Sirius looked grumpy the entire time, and it wasn't until the scarf was secure around his neck that he allowed a relieved smile to float over his features. Remus kissed him then, more on impulse than anything, and he left his lips lingered on Sirius's until he felt them warm up and kiss him back. He drew back slowly and was delighted to see that Sirius's face was bright red and his breathe stuttered out into mist. Remus knew that it wasn't supposed to work like that. They weren't supposed to work like that, and judging by Sirius's uncomfortable expression, he knew they had just ventured into unknown territory. But when Sirius hastily grabbed Remus's ass and shoved against him roughly, grinding into him through their winter pants, Remus knew that the moment had passed and that unemotional hunger was back in Sirius' eyes. He never told Sirius, but the disappointment nearly overshadowed the lust.
The first time Sirius kissed him with meaning was after they had been attacked by Death Eaters in an alley. It had been the four of them as usual, enjoying a night out in Diagon Alley and a tour of the local pubs. A man had reached out and snatched Lily from James' hand as they were walking past an alley, and the three of them had nearly ran over the two Death Eaters in their pursuit of her. A fight had ensued which lasted well over five minutes as spells flew this way and that. At one point, Remus had been distracted by one of the men while the other fired the killing curse at him. He would have been hit, had Sirius not deflected it desperately, sending it back toward the Death Eater and efficiently immobilizing him. Sirius had grabbed Remus off the ground with such force that Remus was for a moment scared that Sirius was going to do something bad until he felt lips crashing into his. The kiss was so strong and so sincere that Remus was stunned for a few seconds until he eagerly returned it, feeling Sirius clutch at the back of his neck and his heartbeat thumping wildly in his chest. Remus felt Sirius tremble under his touch as they broke the kiss, but he kept his forehead pressed against his. 'Don't ever put yourself in danger like that again,' Sirius had whispered harshly, grabbing either side of Remus's head. 'Don't ever do that to me'. The unspoken vow passed between them, and Remus was scared that he'd never feel such emotion from the man in front of him ever again. He thought about that kiss years after Sirius had passed away, silently and bitterly cursing the man for breaking their promise.