Nothing changed.
Siirus, ever dramatic, rather thought it would. Surely the sky would pour down firey vengence, or he would wake up shriveled and old with sin? (He, Sirius Augustin Black, was not supposed to want his best mate. Especially if said mate was male. And a werewolf. And, worst of all, utterly and completely straight.) Instead he woke up to sun streaming through the dormitory window, James's snores loud in his ears.
(Remus wasn't in his bed; Sirius, in lieu of actually praying to a higher being-- not done, y'know, him being a Black and all that, sighed with relief.)
In the Great Hall he moped over a bowl of brown sugar with a side of oatmeal, and decided Something Must Be Done. Perhaps he could bribe Bellatrix to hex his head off...
"Morning." Sirius knocked his bowl halfway across the table and wished he was dead. Gone, buried, pushing up daisies, anything to get him out of the sad excuse for a life he was currently stuck in. Remus looked at him quizzically. "You look rather peaky. You're not getting that flu that's going around?"
Sirius looked around frantically. Could Remus really not see the big neon sign over his head that screamed, "I Want Remus Lupin!"? ...Perhaps not. "Nrrgh." He managed, after many seconds' worth of panicked thought.
Remus smiled slightly, and gave him a look of polite confusion. Sirius hastily amended, "Flu. Yes... It's very bad and contagious. And all that. You might want to avoid me for a long time." He coughed violently.
"You want me to go with you to the Infirmary?" Remus asked, concern evident in his voice.
"No!" Sirius shot back, springing up. "No, that's alright, I'll just go by myself. Don't want you missing classes or anything." He nodded empthatically, turned on his tail, and practically ran from the hall.
Remus sighed and turned back to his breakfast. Perhaps it would be better if he didn't tell Sirius he knew he liked him. After all, he didn't want to explain how his best friend could have possibly died of embarassment.
"He'll figure out sooner or later that he talks in his sleep." He said to himself, and took a bite of sausage.