I don't own Harry Potter...well, not in this reality anyways.
RLSB marshmellowy soft and sugary sweet fluff to follow. Brace yourself, lads.
"I love you, Remus!"
"Damn it, Sirius! Stop saying that, it's not true," argued Remus, frowning with disbelief.
"Yes it is," replied Sirius, fervently, "Merlin's balls, how do I convince you of this?" he continued, shaking his head, gently, "look, Remus, I love you. And it's not an issue that's up for contestation."
"You can't love me."
"I bloody well can and I bloody well do! You're just, you're going to have to accept it, it took a lot for me to pluck up that Gryffindor bravery and tell you this so you're going to listen to me, you're going to accept my lovey-dovey feelings for you and after I'm finished explaining to you just why I am in fact, in love with little old deliciously delectable you, then you can talk, by the Founders you can even protest then – if you feel you really must, okay?"
"Okay," was Remus's soft reply, his face still a picture of disbelief.
"Good," said Sirius, he swallowed nervously and then begin, determination practically pouring out of him, "I love you. I have loved you for the last two years or thereabouts, before that I figure it was more of an infatuation. I love everything about you. I love the way you do things, the way you act, the way you behave...I love how you breathe, you breathe just like everybody else does, you know. But somehow, you give it that little bit extra, that Remus Lupin edge. It vexes me, really. I love how you talk, how you move and I love that you wrinkle your nose when you're amused at mine and James's immature antics but don't want to admit it. I love that little noise you make when you're about to sneeze, I love that little sigh you make when you're half asleep, I love that little sound you make when you're so absorbed into a book and don't even realise it, hell, I love all the noises you make."
Sirius paused for a moment to take a deep breath and gauge Remus's reactions, Remus for his part, just looked on, utterly speechless. Sirius soon continued, "I love the way your hair looks when the sun shines on it and I love that I notice the sun shining on your hair as well as loving that I notice loving the sun shining on your hair. Ridiculous, yeah, but there you go. I love the way you make me feel when you're not touching me and the way you make me feel when you are touching me, whether it be inadvertently or otherwise. I love the way you never judge me for whatever leftover pureblood prejudice I contain, you never try to change how I think. I love that you understand some of that stuff still matters to me, even though I hate it. Nobody else gets that. I love that you never begrudge me and James's for keeping secrets and jokes from you and Peter, I love how you get that James is like my brother and accept the two of us as such. I love how you yawn first thing in the morning, I love how you're completely oblivious to the looks you get from all the people who think you're hot. Dare I say it, it's even cute. I love how your hips rock back and forth when you pace about a room. I love your scars, I wish you didn't have them but for your sake, not mine. Personally, I find them undeniably sexy."
Seeing Remus give a slight embarrassed smile at this, Sirius went on, "I don't love the way that you're sometimes so self-depreciating and self-conscious, especially when you've got the nothing to be self-conscious about what with you being the most beautiful, funny and sweet creature in the world and all. I also don't like that you have this effect on me, you make me crave you and turn me sickeningly sentimental - at the same time, I love that you have this effect on me. I love how you frown oh, so disapprovingly at me when I do something you're not entirely happy about. I hate how you make me feel when I disappoint you, it's torture. I love how you raise your eyebrows in that 'sceptical disbelief' sort of a way when you're pretending to be shocked. I love how your favourite type of chocolate is anything made by Honeydukes and I love how you look while eating it, savouring every bite and bit of flavour. You might not actually want to know this but every time I see you eating chocolate I just want to jump on you, snog you half to death and taste every inch of you. I rather imagine you taste just like the chocolate you love so much with a hint of cinnamon. I imagine how you taste a lot actually."
Sirius smirked and noticed the faint blush rising on Remus's cheeks at the most recent of his confessions, "I love how you blush too. I love wondering how many different ways I can make you blush. I also love how something as pointless and dull as getting permission to go into the restricted section makes your eyes light up with exhilaration. I love that unlike everybody else, you never tried to impress me, you just were, you just existed just as you are and Merlin help me, I even find your unnatural obsession with muggle literature somewhat admirable. I love your hands and the way you fidget with them. And they're just so, they're so, so smooth and flexible, so unexpectedly strong and light and just so very Remus like. I love imagining the things you could do to me with those hands. I love your feet which is weird because I hate feet but yours are strange and bizarrely delicate and just plain lovely. And buggering fuck, Moony!, you've got sensational ankles. They drive me wild and I can honestly say I've had more than a few dreams at their expense if you catch my driftage. I love you, in so many ways, I love you physically, mentally, emotionally, sexually, sensually, whateverally. Every new thing I learn about you just increases my lewd and non-lewd adorations and if you don't believe me by now, I really don't know what I can say. I mean, I'll continue saying stuff because you're my little teacup and I love you and shit, I don't know how else to convince you. Remus, I just need a chance..."
...and as Sirius continued his rants over his affections Remus stared back at him, frantic and wide-eyed until eventually he shut Sirius up, (an accomplishment in it's self), by firmly and soundly kissing him on the mouth. Remus tentatively leaned back to try and gleam a reaction from Sirius's expression. Sirius stared back at Remus with a glazed look for a few moments before finally he kissed Remus back with the passion of at least two years of unrequited desire and unadulterated passion. Withdrawing slightly he murmured gently against Remus's lips, "I love you." Contrary to prior complaints Remus simply replied, "I love you too."
I did warn you about the fluff levels. And well, would you expect Sirius Black to express his feelings in a less drastic way? ...review, please?