Ingrid crashes the party.

After handing off the Box to Annette, Ingrid's day had continued mostly as she was used to. In a way, since taking care of the Box had been cleaning up one of Sylvain's messes, that part was also business as usual. When she left Annette at the library, she'd spent some time practicing with Felix, never saying a word to him about what else she'd been up to that day and departing before she could bump into Annette a second time. She'd enjoyed a hearty early dinner at the dining hall by herself, then returned to her room for a quiet night of diligent study, early sleep, and...

... Staring at her ceiling, feeling restless and muttering about Cherry Pie under her breath. "It's so frustrating! Why can't I get that particular song out of my head? For all I know, even if I have the misfortune to run across that box again, that song might be one of a thousand it plays... As a matter of fact, the other songs I heard were quite different from it. There's a chance it's an outlier from the others. In a way, that makes it special..."

Ingrid tried to **** her brain to turn off and let her sleep by shutting her eyes and remaining still. As the moments passed, she was tossing and turning again in her plain shirt and shorts, chasing sleep that never came. "Why?! Isn't a good night's rest the reward of a knight who eats well and trains diligently?" She clutched her pillow, thinking she hadn't ended up this hard for sleep. Not since she'd learned Glenn died...

...

As soon as that gloomy thought hit her brain, Ingrid knew there was no way she was going to sleep. More than anything, it made her furious at herself. "I've wasted so many thoughts today on the lyrics to a moronic song and Sylvain, of all people... It's like I've forgotten the purpose of my being here. I haven't got hours to waste...Ugh! When I think of it that way, I regret giving Annette that box. I bet she's fallen into the same pitiful pitfall of meaningless distractions as me. Well, if I'm not going to sleep, anyway, I ought to pay her a visit and make sure she's well..."

Ingrid rose, trading the plain shorts of her sleepwear for a more decent pair of breeches. She considered if she should bother fully disrobing and redressing. She'd have to pass one other room, then descend the stair: Annette's room would be on the first floor, just around the corner. At this hour of the night, most responsible students would be asleep. She trusted she could make the trek without being seen. Even still, she tied her hair in a quick braid reflexively before leaving.

Not realizing she was mimicking another Blue Lion from earlier that night, Ingrid peeked her blonde head out of her doorway and peered down the hall. No other eyes met her brilliant green ones. The knight-in-training snuck out, down the stairs, and...

Before she even got down the staircase, she nearly tripped as her feet suddenly began rebelling against her. Her whole body pushed itself against the adjacent wall, pressing her cheek against it and letting her better hear the unmistakable rhythm coming through it. If it wasn't so quiet and her ears weren't attuned for it, she might have missed it; that was more of a curse than a blessing at the present moment, however, as she found her hands fanned against the wall and her hips jerking like she was humping it.

"I can hardly believe it... Annette's listening to it at this hour?! What is she thinking?" Ingrid hissed out of the side of her mouth that wasn't kissing the wall, forcing her uncooperative body to slide its way down the staircase. When she reached the landing, she tore away towards the center of it, put her fingers in her ears, and stormed down the remaining flight, determined not to let the music into her brain. She turned the corner, prepared to march straight into Annette's room.

At the end of the hall, she saw a lantern-lit shadow stretch around the corner. Covering her mouth to stifle a yelp, she quickly opened the door to Annette's just the crack she needed to enter, slipping through hastily and shutting it behind her in one swift motion. Once on the other side, knowing she was already fighting against the control of the Box, she stepped forward, intending to lunge for it and put a stop to Annette's irresponsibility-

A single step was enough for her to trip on one of the two people in the room, leaving her pratfalling face-first onto the carpet. With whatever authority she'd planned to give herself now out the window, Ingrid lay face down on the floor, nursing her nose while helplessly snaking her butt in the air.

The small surprise she'd gotten upon entering, however, was nothing compared to the surprises still in store once she got a look at who else was present. "Annette and... Mercedes?! Annette, you didn't...! No, before that, why are the two of you-"

"Oh, thank the Goddess you're here!" Mercedes clapped her hands in a gesture of prayer. That gesture was the only thing hiding the cream-colored bra she was wearing, and the hanging of her impressive breasts was the only thing hiding the front of her matching panties as she twerked her butt in the air, knees on the floor. The curves of her hips and her pleasantly thick legs could be seen alongside her.

"Wuh... what's going on..." Ingrid muttered dizzily, barely aware of Annette approaching from behind as she fought her way to her feet, hips shaking all the while. "Mercedes are you... Y-you're here against your will? Oh dear, how long have you two been **** to dance here?"

The older student shook her head. "No, that's not it. I'm glad you're here, Ingrid, because you simply must judge our contest! You have to tell Annie that her dancing is much cuter than mine."

Ingrid realized she wasn't putting the pieces together correctly. "W-what... Who... W-why are you in your underwear?!"

Annette's voice came from behind her head. "The better question is why aren't you? Let's just get you out of these and into something more slumber party appropriate!"

Whatever thought Ingrid was forming turned into a startled yell as Annie's hands hooked into the sides of her breeches and yanked them down, leaving Ingrid standing in her underwear. Her panties were terribly plain, but well-fit to her tight, hard-earned figure. She heard her two classmates "ooh" and "aah" as she struggled to try and get her pants back up, an idea that her body didn't seem to appreciate at all. Immediately, her arms **** themselves above her head. She bent her knees to stop the pants from falling to the floor, an act of defiance that only left her looking like her pants had slipped off from the shaking she was doing with her lower body.

Annette circled around to Ingrid's front, jerking her hips from side to side as she moved. Ingrid could now see she was wearing a colorful bra and panty set, powder blue and decorated with white stripes and frills. The mage was shaking her shoulder-length red hair, rarely seen down as it was now. "Ingrid, Ingrid, Ingrid... If you'd come here in anything with a splash of charm, you'd be crowned champion in our contest immediately! We'd have no chance to compete. Dressed like that, though, it's like you're ruining yourself on purpose."

The pulsing music blasting from the Boom Box next to her, the laughter and teasing from both of her friends, the shameful state of her dance... Ingrid couldn't form her thoughts, but she was preparing to furiously erupt and have her say, regardless.

However, no sooner had she opened her mouth to **** out a shout than Annette had popped one of Mercedes' baked treats into it. Ingrid could get mad at a lot of things, but never food, especially some of Mercedes' handiwork. She grew gradually more calm as she **** it down, although her judgmental expression remained. "Annette, I don't know what's possessed you to do this, but... Hold a moment." Even though she said that, none of the three women held at all, continuing to energetically shake their hips as Ingrid continued. "Annette, how are you moving about freely?"

"Eheh... Are you impressed? After just one day of study, I've already learned this much about our little pal, here." Annette sauntered over to where the Box was set and bent over it, patting it on its top handle affectionately while continuing to shake her panty-clad bottom at the other two. "So, it does make you dance, just like we thought... Slutty doesn't like it when you don't dance to his music. The trick is that you can actually do just about whatever else you want while you dance, as long as you make the dancing part of it. You can even turn it off, if you like... You just have to promise Slutty that you'll come back and dance with him again."

Ingrid felt vastly uncomfortable about Annette's treating the dangerous magical item as a pet, but she had to admit, the theory Annette was proposing was useful information. "I have to say, Annette, that doesn't make me feel much better. You're telling me that the only way to appease this infernal thing in the short-term is to willingly devote yourself to it in the long term. That sounds like a devil's contract to me."

Annette frowned, wagging a finger at Ingrid even as she waved her hips behind her. "Come, now! All Slutty does is play fun music that makes you want to dance. We can train, study, eat, do chores, and still make time for a little dance, can't we? I think it's a fair trade-off for all the fun he provides."

"That's..." Ingrid started to complain again. The defiant part of her that had planned to march in and give Annette a piece of her mind suddenly felt very weak. It was a hard thing, acting the chiding schoolteacher to two other women her own age when she ought to be sleeping... and without pants, besides. "I didn't give you the Box for your to have fun, Annette. I gave it to you for responsible study. If you play with it this late at night, someone's going to find out about it. I could hear it from the hallway."

"Barely, I bet," Annette complained, resistant even to the idea of turning it down. "Besides, I'm sure it's not bothering anybody... It's fun for everyone!"

"Maybe you're having fun, but I hardly think this music would be to everyone's tastes. Maybe if it were that Cherry Pie song-"

"Aha!" Annette shouted as though she'd just won something. "I knew it! You're still thinking about that Cherry Pie song you danced for Sylvain, aren't you?"

Mercedes reacted with a shocked gasp. "Sylvain? Oh, my... What were you doing dancing for Sylvain, Ingrid? It sounds like there's a juicy story I haven't heard yet..."

"It was a stupid, boyish prank!" Ingrid defended, feeling the cheeks on her face redden as her long legs continued to carry her. "There's no story at all. And the song, it's nothing special, it's just... w-well, it's less fast-paced than these. The dances to these are just, you know, empty motion... The dance to that felt like it was more particular, like the showmanship was more involved-"

"Oooh, so you were dancing for him with 'involved showmanship!'" Annette cooed.

"Look, I had no say in what song he picked..."

"You think he picked it for you?" Mercedes commented, her eyebrows arching in surprise. "Oh, dear... That is somewhat special, then, isn't it?"

The two mages continued to tease and laugh at their friend's expense, occasionally placating her with treats. All the while, the music and the movement never stopped. Mercedes had been worried about what dancing a full song might do to her; however, as the night dragged on, the tape played start to end through song after song, with not so much as a groan of pain from any of the Blue Lions women. Nobody, not even Ingrid, made a move to turn it off...

... Until, finally, Ingrid let out a long yawn, in the middle of dropping it to another set. "Ah... Truth be told, I only ever meant to come here and give you a talking to before heading back to bed, Annette. Fun is fun, but we have responsibilities come tomorrow. The other houses look up to us: we can't afford to be tired and distracted during studies and training."

On this point, Mercedes agreed. "Annie, Ingrid's correct. We can have another party another time, okay?"

"Hmph... But we never declared a winner of the twerking contest," Annette pouted, although she did finally move her ass over to the Box and shut the thing off. When she did, the three almost let out a long sigh in unison, and couldn't help but laugh together when they realized it.

Ingrid was eager to leave, but felt bad leaving Annette on a sour note (largely because she was worried that, if she did, it would only exacerbate the woman's newly-discovered capacity for mischief). "Honestly, doing a contest like that right now is a bit silly, isn't it? None of the three of us has really practiced for such a thing. Wouldn't it be better if we met and tried it again once we've all had a chance to get used to it? And at a more reasonable hour of the day, preferably?"

"Leave it to Ingrid to bring training into something like this!" Annette giggled, clearly in a better mood at the suggestion. "Well, then, it's settled. We'll each take turns getting a little practice in with the Box tomorrow, and we'll consider doing a real contest tomorrow night."

"I thought we were doing makeup tomorrow night?" Ingrid reminded her. "Not that I care to, mind you..."

"We can do both, of course. Ingrid, why don't you take Slutty back to your room and have first crack at it tomorrow? You can trade it off to me around noon, and I'll give it to Mercie later in the day."

"... I can't imagine myself devoting time to this thing early in the day, but I can no longer trust you if I leave it here. I'll have to take you up on that offer," Ingrid agreed. She picked up the Box, turning for the door. "With that, I wish you ladies good night... Hopefully, we'll all sleep better after the exercise."

"Pfft..." Annette giggled through her hand, wearing a big smile. "Good night, Ingrid... I-it's a little drafty tonight, though, isn't it? Are you going out like that?"

Ingrid realized that she'd gotten so comfortable, she'd completely forgotten her breeches on the floor. Once again, a deep red flush crossed her face as she set the Box aside and hurriedly pulled them up. Perhaps to recover from her humiliation, she tried a comeback, wearing a crooked smile. "I thought you said I looked better without them?"

"Obviously," Annette agreed, and the two laughed together again.

... Mercedes watched the two happily trading barbs in their underwear with a funny smile, a strange thought coming into her head. She voiced it, to herself as much as the other two. "Do you think this Box does anything we don't know about?"

Ingrid grew serious again as she considered the question, holding the Box once again. "I'm certain it must. No one capable of an invention of such advanced technology would spend that effort just to let women have an amusing night with a twerking party."

Mercedes nodded, although she seemed more bothered than when she'd asked the question. Something about Ingrid's response made her uneasy, but she couldn't put her finger on what. "So... you're still not comfortable with the Box, then? It struck me that you seemed to warm up to it rather quickly."

"Absolutely not," Ingrid confirmed. "I still think, though, that it's important that we use the Box as much as we have to in order to get complete knowledge of it. We have to master it while it's still a secret."

"... You mean 'study it carefully?'" Mercedes pointed out, tilting her head curiously.

"Isn't that what I said?" Ingrid yawned helplessly again, rubbing at one of her green eyes. "Well, good night, again."

Mercedes watched her go, then began dressing herself again. "Annette... Thank you for inviting me over for such a fun party. I had more fun than I can remember in a long time. It really meant a lot to me that you complimented my dancing, even though I'm only half as good as you. That was very kind of you."

"Mercie!" Annette complained in spite of her friend's warm words. "How many times have I said tonight that you are blessed with a gift from the Goddess herself? There's no reason to be timid or humble when you're armed with a holy weapon like that!" To accentuate her point, the younger woman gave her older friend another swift swat on the behind through her chaste nightgown.

Mercedes gasped, nearly dropping the treats she'd gathered to take with her. She looked back at Annette with a red face and big, shocked blue eyes, hesitating. Finally, she spoke what was on her mind. "Annie, um... That was a fun bit of teasing and playing around at the party, but with the party done, isn't it strange? I don't think you've ever... touched me or teased me like that, before tonight..."

Instead of coming back with another zinger, Annette herself immediately went red and put her hands to her face. "Oh my gosh... You're right! I'm sooo sorry! That's very uncharacteristic of me, isn't it? I guess I got caught up in the mood... and I never saw your body like I did before today... a-and I filled up on so many sweets so late, I guess I just got hyperactive! I'm so sorry if I made you uncomfortable, Mercie."

"It's all right, Annie," Mercedes replied with her usual peaceful smile. "Let's just all agree not to get too carried away with our fun... All things in moderation, the Goddess teaches us. When 'things' include a music box that controls bodies, I think it pays to be prudent, don't you?"

"Yeah," Annette agreed with a nod and a gulp. "Well, I'm glad we gave it to Ingrid first. Responsibility is her middle name. If anyone can be prudent about that funny whatchamajig, it's her."

The two friends wished each other good night and, at the right moment, Mercedes snuck out, leaving Annette to her rest.