Sirius was careful that his wand was pointed at the little mouse on the desk. Inhaling, he concentrated and cast the spell: "Confundo."
Around the class, students cast spells on their mice while Professor Adlebert issued warnings: "Be careful where you point your wands!", "Concentrate.", "Not like that Pettigrew."
"Not bad," Sirius proclaimed as his mouse ran in circles. Remus at the desk next to Sirius, nodded and took his own breath, screwing up his eyebrows in concentration.
At that moment, Sirius's very befuddled mouse had the distinct discourtesy to run between the desks and down Remus's trouser leg.
"Confundo!" cast Remus just as he sprang from his seat. His wand, from which his spell flew, was no longer pointed at his own fat mouse.
Rather, it was pointed directly at Sirius Black.
Sirius's very first impression was that the world had gone... intoxicated. It spun a bit. When objects moved around him, they left resplendent trails of sparkling incandescence. "It's lovely," he muttered.
"Oh no, I hit him!," cried Remus.
Sirius, however, had heard something very different. The garbled words from Remus's mouth had definitely, absolutely, without a doubt sounded like, "I want to kiss him."
For Sirius, the fact that Remus Lupin was sitting perfectly still made capturing him in a kiss no less difficult, for Sirius's world was spinning. Only once he had Remus's lower lip within the grip of his teeth did he answer, "I want to kiss you too."
To Remus, it sounded far more like, "Aye vant choo viss chew choo." Nevertheless, Remus obliged.
"Ahem," interrupted professor Adlebert. "Oh dear. Why does this happen every year? There is a reason I warn you to be careful where you point your wands."
Remus broke the kiss only when Sirius fell over onto the floor giggling.