This is as fluffy as I'll ever get. AU where Sirius is a tired art student and Remus is the grumpy literature stoner student who lives in a tiny flat on the other side of the street. Over Thoreau and Terpentine they fall in love.
"But why?" Remus asked, when they broke apart long enough for him to form an actual sentence. "I'd make a terrible boyfriend."
"I'm sure it won't be that bad." Sirius mumbled, from where he was trailing kisses down Remus' neck.
"I'm awfully grumpy in the morning."
"Hmmm I'll make you coffee."
"I'll smoke on your fire escape and leave the window open."
"Good, then I can join you."
Remus let out a moan that was half frustrated, half aroused, and gently pushed at Sirius' shoulder. "I don't think you get it. Terrible, Sirius. I stay up all night some nights. I will sneak out some mornings. I'll only call you when I'm high."
"Will you pick up when I call you?"
"Probably only when I'm high."
"Considering how you always reek of weed I guess I can live with that."
"You're such an asshole."
"Alright, you know what, fine." Remus grabbed the front of Sirius' shirt and pulled him up in a fiery kiss that knocked the air out of Sirius' lungs. "I'll be your fucking boyfriend."
Sirius hummed against Remus' lips, pleased with himself and the way this entire evening had turned out.
"Insufferable." Remus growled, attempting to press himself closer to Sirius even though there was no space left. "Frustrating, spoiled, ridiculous, terpentine-reeking, tormenting, ..."
"Keep talking dirty to me." Sirius murmured, lips brushing over Remus'. "You're so good at it."