I'm the Harpies Captain this season. Thanks to my team and Charlie for beta-ing this. Word count is 916.
For Spider Kid.
Severus fixes Minerva with an unimpressed look as he folds his arms over his chest. "I don't see why we are doing this."
Minerva sighs heavily. "Don't be such a drama queen, Severus. It's really unbefitting. Dancing won't kill you. As the Slytherin Head of House, you need to learn to be able to teach your students."
Severus doesn't uncross his arms as he says, "You could teach all the students since you are the only Head of House that knows how to dance."
"I could," Minerva agrees. "However, I have no intention of doing so. Hence why I have taught both Pomona and Filius this dance. You cannot get out of this simply because you don't want to learn. The Waltz is easy; there is no grandeur or dips, just simply twirls. This is why we've decided to teach the students this dance."
Minerva draws her wand and flicks it. The record player in the corner springs to life and music fills the empty classroom. It has no vocals; it's only a smooth melody.
She pockets her wand. She's standing in the middle of the empty classroom, where the desks have been cleared out specifically for dance lesson for all students. She moves her feet a little apart, raising one of her hands. She gives him a pointed look, as she instructs, "Take my hand and put your right hand on my waist."
For a brief moment, Severus considers arguing that it's useless to learn a skill he'll never use again. The look in Minerva's eyes keeps him from doing so. He steps closer and takes ahold of her hand with his left hand while his right hand rests on her waist.
Minerva counts out the steps as she steps forward. Severus steps backward instinctively. She steps to the right and Severus steps with her.
She inhales sharply without stopping. "I would appreciate it if you would refrain from stepping on my foot."
He doesn't answer as he looks down to follow her steps. Minerva says nothing against this, only continuing her counting where she left off before her comment. He manages to keep up with her while he watches her feet.
Minerva stops when Severus has managed several rounds without stepping on her feet. The music has changed; it's a barely noticable difference. "That's better. You've got the steps down. Let's see if you can do without looking at your feet."
Minerva doesn't give him any further warning as she steps forward, counting. Severus hurries to keep up with her. He hears a sharp inhale when he steps on Minerva's foot again. He resists the urge to look down at the feet to follow the steps.
By the time that she stops a second time, he caught on to the steps, finding it easier and easier to keep up with Minerva as she counts. He hasn't stepped on her foot in quite a while.
"Much better," she praises. She gets a gleam in her eyes that causes Severus' stomach to fill with unease. "One last song."
She takes his hand again and steps forward, counting. Severus takes it in stride. He keeps up with her steps, murmuring the cadence under his breath along with her. He prides himself on not stepping on Minerva's feet once.
"Now, we're going to dip," Minerva announces. Severus steps on her foot in his surprise. The pain doesn't deter her.
She moves her hand from Severus' waist to the middle of his back. Severus goes rather easily; Minerva was expecting more of a fuss from him. She lowers him a good distance before pulling him back up.
She picks back her counting where she left off, and Severus keeps up with her almost thoughtlessly. He even manages not to step on her feet, which Minerva is thankful for. Her toes can't take much more.
Dropping her left hand from Severus' waist, she pulls out her wand with her right hand to stop the record player.
"Well, you're ready to teach your students. It's not perfect, but at least it won't embarrass the school," she informs him.
Severus seems to come back to himself. Her narrows his eyes, fixing her with a glare. "You said that there were no dips in the Waltz."
Minerva smirks, meeting his glare without hesitation. "I know. Do you think I wasn't going to have a little fun for myself? Especially after you stepped on my feet so many times."
She doesn't bother telling him that Pomona and Filius caught on much quicker and stepped on her feet far less often than him, which is why she didn't dip either of them. That's just something that she'll keep to herself; there's no reason to embarrass him further.
Instead of complaining as she expects, Severus keeps his mouth shut, his jaw twitching with effort and his cheeks reddening with anger, before he turns on his heels and sweeps out of the room.
Minerva pockets her wand once more. She follows Severus out of the room, back to her office where grading awaits her. The dancing lessons her mother gave her as a child have paid off. She wasn't looking forward to teaching Severus when Professor Dumbledore had given her the task since she knew that he would be the most difficult one, but she found some joy in teaching him.
If she had later used a Disillusionment spell to observe Severus' dancing lesson to watch his students step on his feet, well, nobody had to know.