"Sweetie Belle, could you come here please?"

The filly cringed. She didn't want to go to her sister, she really didn't, but she knew the time had come to face up to the failed and disastrous slumber party plan. It had been two days, and in that time Rarity had not interacted much with Sweetie Belle, instead focused on restoring the shop while her little sister chose to hide in her room. Or more accurately, she had been grounded to her room immediately...once Rarity had hugged her and assured herself the filly was unharmed by her escapades.

"Sweetie Belle. I'm waiting "

Oh. Right.

Inhaling deeply, Sweetie Belle forced herself to exit the relative safety of her bedroom prison and descend the stairs to the boutique. She looked around, somewhat amazed that Rarity had managed to restore it to it's sparkling, organized glory so quickly. And speaking of Rarity...

The fashionista had taken up residence on a large very plush ottoman, forelegs crossed as she waited, and was now regarding her younger sibling with a look of disappointed disapproval. Sweetie Belle gulped. This was not going to end well.

"Y-you wanted me?" She asked, her voice squeaking a little in terror.

It wasn't that she was afraid Rarity would harm her, because she knew that would never happen, but she was definitely anxious and apprehensive about just what her sister might do and say.

"Come sit." Rarity pointed her hoof at a smaller chair before once more returning it to it's crossed place on her chest.

Sweetie Belle obediently trotted over and hopped up in the chair, where she sat with her head down trying not to cry before Rarity even started scolding her. Rarity studied her for a moment, then drew a deep breath.

"Would you care to explain why you thought it would be a good idea to disobey me?"

"N-no?"

"It was not a question, Sweetie Belle."

"Uhm...it was phrased like one though."

"Young filly, you are in more than enough trouble already, do not add to it."

"Sorry, sis." Sweetie Belle's head dropped lower.

"Explain to me what you were thinking." Rarity instructed.

She trying to remain stern in spite of the fact she just wanted to hug her sister tightly and let all this slide. She knew she could not do so, because Sweetie Belle had done something that could have ended in somepony being hurt or worse, and she had to face the consequences for that.

"I was mad." Sweetie Belle admitted shamefully. "I really wanted the party, yeah, and I was mad we couldn't, but I would have waited anyway. Then you said we weren't capable of doing it alone and well, I just got madder. So I planned on doing it anyway, and I thought if we were careful you wouldn't even be mad."

"Darling, I would have been upset with you regardless. Not because you had the party, but because you disobeyed me. Even if nothing had been damaged, it would still have been disobeying. Do you understand that?"

"Yeah. I just wanted the party, and I wanted to prove we could do it alone, but now I know it was just really stupid and I should never have done it."

"You're right." Rarity nodded. "You shouldn't have. And I am very disappointed in you, Sweetie Belle."

"You still love me, right?" Sweetie Belle looked up then, tears in her eyes.

Rarity gasped, and quickly grabbed the filly, pulling her into a warm and gentle hug as she nuzzled her with all the love she could put into it.

"Oh darling, of course I still love you. I'm disappointed, but I still love you very much. And nothing you do is going to change that. I promise."

"Pinkie promise?"

Rarity had to smile at the question. She nodded, releasing Sweetie Belle with one foreleg so she could use her hoof to go through the required motions of the promise.

"Cross my heart and hope to fly, stick a cupcake in my eye."

Sweetie Belle smiled, but it quickly faded as leaned into Rarity with a heavy sigh.

"I am really in big trouble, aren't I?"

"You really are." Rarity rubbed her muzzle with a hoof and inhaled. "Darling, what you did was very dangerous. You really don't know how to do a party properly and safely, which is why I told you no. And by doing it anyway you put your life and your friends' at risk. I cannot just let that go."

"Am I grounded forever?"

"No." Rarity hesitated, not wanting to go on with what she planned, but knew she needed to. "Not this time. This time I am going to give you a spanking "

Sweetie Belle felt the tears well up and she shuddered slightly. Rarity hadn't spanked her in months, not since she and the Crusaders had gotten the bright idea to use Twilight's lab for science experiments. She wasn't thrilled about the impending punishment, but she couldn't very well honestly argue she didn't deserve it. She took a deep breath and looked up at Rarity.

"I guess I deserve that. But I wish you didn't have to. It hurts."

"I know, darling." Rarity nuzzled her. "How about we get it over with and then we'll have ice cream and I shall read you a story?"

"Ok."

"That's my brave little filly."

Rarity set her down and got up, leading the way upstairs. Sweetie Belle stayed by her side, feeling her stomach doing nervous flip flops as each step took her closer to her doom. Once they crossed the threshold into her room, Rarity made her way to the bed and sat down, at the same time floating over Sweetie Belle's mane brush and depositing it next to her on the bed.

"Come here, little one "

Sweetie Belle hesitated, and Rarity didn't force her to move. After a few deep breaths, the filly crossed to her and stood at her side, visibly trembling but not making any attempts to flee or talk her way out of the situation. Rarity caught her up and laid her gently in place over her lap, making sure she was as comfortable as one could be in that current position. Her left foreleg wrapped around her small body, holding her securely. It felt like a warm hug, and Sweetie Belle held on to that thought to steady her rising panic at what was coming.

"Alright, Sweetie Belle. Why are we here?"

"Because I disobeyed you and in doing that, it put lives in danger. And I'm sorry."

"I know you are."

Rarity slightly tightened her hold on the trembling form, and brushed her tail aside before bringing her hoof down in a firm swat on each side of her flanks. Sweetie Belle jumped, startled at the sting, tears filling her eyes all over again. Rarity found her rythm easily, the seats falling evenly on first one side then the other, each one carrying a mild sting that steadily built up into a not so pleasant burn. She wasn't swatting with much strength at this time, since she was only warming up the filly's flanks for the slightly harsher punishment of the mane brush.

Sweetie Belle started to squirm a little as the smacks continued to fall, tears starting to spill from her eyes as she thought about the actions that had landed her here. Rarity paused and her magic enveloped the mane brush. She tapped it lightly on Sweetie Belle's flank to let her know what was next, and nearly called the entire punishment off when the filly let out a somewhat pitiful whimper and tensed up on her lap. Steeling herself, she lifted the brush, and brought it back down on its target with a swift crack.

"Ow!" Sweetie Belle yelped, jolting and starting a frantic attempt to escape.

Rarity tightened her hold further, and planted a matching, hard smack on the other flank.

"Owww!"

The struggling increased, but Rarity had a firm hold and her sister was not going anywhere until she said so. She took a breath, and delivered a rapid volley of smacks to the already rose colored flanks.

Smack Smack Smack Smack Smack Smack

It was at this point that Sweetie Belle broke down and started crying in earnest, spitting out broken apologies and swearing to be good forever. This would have made Rarity smile at any other time. She needed to be sure that the lesson stuck, so she brought the brush down again rapidly.

Smack Smack Smack Smack Smack

"Owww! I'm sorry Rarity!" Sweetie Belle wailed, before her body went limp across Rarity's lap and she just sobbed miserably.

Rarity paused, tears in her own eyes, hating every second of this but knowing she had to do it for her sister's sake. She did not have the heart to keep the punishment going any longer. It was time to simply drive the point home and be done with this, for both of their sakes.

"Just a few more, darling, I promise. And then we'll be done."

Her only response was sobbing, so she took a final steadying breath and delivered a flurry of sharp swats to her sister's more tender sit spots, prompting a broken wail followed by more sobbing. Throwing the horrid brush away from her, Rarity gathered Sweetie Belle up in her forelegs and hugged her tightly, soothing her as her own tears fell unchecked.

"I'm sorry." Sweetie Belle sobbed. "I'll never do it again, Rarity, never. I'm sorry."

"Shhhh. I know darling. I know." Rarity held her close to her chest, nuzzling her lovingly. "I forgive you, little one. And I love you. So much."

It took several minutes, but Sweetie Belle managed to calm down, her sister's words of love and reassurance washing over her as she held her safely and snugly in her grasp. Once the storm of sobs dwindled down to sniffles and hiccups, Rarity kissed her head.

"You alright now, darling?"

"I think so." Sweetie Belle sniffed. "My flank hurts, but I did have it coming." A sniffle made her pull back and look up. "Rarity?"

Rarity looked back with tears in her eyes, and Sweetie Belle blinked, aghast.

"I'm the one who got her flank spanked, why are YOU crying??"

"Because I love you and I do not like having to do that to you." Rarity sniffed and took a breath. "But because I do love you, I will do it when I have to."

Sweetie Belle nodded silently, knowing she would keep her word. Rarity smiled

"Alright, enough tears. How would my little sister like that ice cream now?"

Punishment forgotten, Sweetie Belle leaped off her lap.

"Last one to the kitchen is a bad dragon egg!"

"Oh it is on, little sister!"

Laughing, they rushed from the room, and a sleeping Opalescence suddenly awakened and went scrambling out of their path before scolding them soundly from a safe perch on a high shelf.