It is a known fact that Remus Lupin cannot dance. This year could be different. Remus/Sirius.
This year was going to be different. Remus was sure of it. He had checked out from the library numerous books on the science and methodology of dance, even going so far as to ask the king of dance Gilderoy Lockhart himself for some help. This resulted in sneaking out after curfew - a very un-Lupin act indeed - and spending night after night learning the art of the dance floor from Prince Lockhart.
During these trials and tribulations to earn himself a place among the learned dancers, Remus never stopped to consider who he would ask out as his date for the ball. After much consideration and thought, he sent a letter to Lily asking her. He never once thought that Lily would say yes, as he believe she was dating James - but, to his surprise, the next morning Lily passed by him in the hallways and mouthed "Yes" at him. Success!
Or so he thought. The day before the ball, Lily came down with a bad case of strep throat. She laid in bed, feverish, apologizing incoherently to Remus that she could not make it (when she wasn't screaming her throat raw at James for being an idiot and not asking her out himself).
The morning of prom there were no classes. Remus spent an hour lying in bed, staring at the ceiling, torturing himself by reviewing all the dance steps he would never use again. The step-and-dip. The two-step. The glide. The twirl. The tango. All now deemed useless by a pitiful virus. So he sulked (although he'd never admit in a million years he was a sulker).
Hours later, a familiar mop of black hair appeared next to him. "Whattya doing lying in bed, Moony?" Sirius whined. "It's prom! You should be out necking it with one of the fifth-years. Come on, get up!" He dragged Remus out of bed and into a chair in the empty common room.
"I'm not going," Remus said blearily.
"I'm going to pretend I didn't hear that," Sirius responded, looking through a chest he had pulled out of storage just for the occasion. "Which color do you like better - teal or turquoise?" He made a face at Remus. "Mind you, my family never had much taste in formal attire."
"I'm not going."
Sirius slammed the chest shut and pushed it away with a gliding motion. Remus jumped slightly at the sudden burst of noise. He was even more startled when Sirius grabbed him by the wrist and had him standing in the middle of the common room in an unfamiliar embrace.
"We're gonna dance, whether you like it or not," Sirius said huffily, and it was then that Remus realized that his fellow Marauder had been dumped by his date, a nameless fifth-year Ravenclaw.
Remus closed his eyes and in his mind he could see the main hall transformed into a first-rate dance hall, lit candles floating in the air, couples in fancy dress circling around the floor.
He opened his eyes to see he had unconsciously taken Sirius' hand and they were now in typical waltz position; Remus had his right hand and Sirius' left hand clasped together in the air, outstretched, while the opposite hands were resting together on Sirius' hip. The canine Animagus smirked and asked, "Shall we dance?"
"Indeed," said Remus and in seconds they were slow waltzing in lazy circles around the room, their gaze steadfast on each others' faces. A soft smile appeared on Remus' face. No words were spoken as the couple switched to a slow tango. Their bodies moved together in a silent partnership, a regular Astaire and Rogers, a perfect union. Sirius felt Remus take control of the dance, doing the movements reserved for the male lead. He marvelled at how quickly his friend was taking control so quickly; in fact, Remus was astonishing himself in how good he was, although he tried not to think about it too much.
That was when he went for the dip and, in the process, ended up dipping himself. Sirius panicked and - to Remus' horror - let go. The young fair-haired boy dropped to the floor, his back and bottom making a painful contact with the carpet. He scrambled to get up and resume, grabbing at Sirius's robes. This only caused a shocked Sirius to slip and fall on top of Remus, and they both began panicking to get on their legs. Their frantic movements only tangled up their robes even more and minutes later they conceded defeat, lying on the floor next to each other, panting breathlessly.
The silence that lay in the air was broken by laughter. Sirius grabbed his sides as he began snorting, then chuckling, then progressed into full-blown howling and screaming in glee. Remus' face was one of complete shock and for a moment Sirius felt a bit of guilt. That was until Remus began laughing as well, like he had never laughed before in his life. Their voices mingled and joined together to form a most uplifting chorus that could be heard in the hallway outside.
Late that night, as all the dates filed into bed way past curfew, Remus Lupin lay in bed, staring at the ceiling, wondering what the funny fluttering in his stomach meant.