Celestia's Secret

Luna smirked as she jumped up, grabbing a new pair of panties with the tips of her fingers. “What are these?” she asked, holding them up as her sister’s magic returned the other undies back to their rightful places. The panties in her hand were made up entirely of a white, delicate, and flowery lace that featured a small bow at the front.

“That, my dearest sister, is a thong.” Celestia clasped her hands together with glee, her upper arms pushing her breasts together. “They are most certainly my favorite style of panties, and nothing makes a mare feel sexier!”

“But... there’s no coverage in the back, though,” Luna said.

“Exactly! They’re perfect for those times when we have to attend a Gala or another similar event. Your old panties, and especially your bras, well... we were all able to see lines.” Celestia threw on a sheepish smile.

“Lines?” Luna cocked her head to the side.

“Yes. Everyone could see the outline of your undies, and in a slim, form-fitting dress, that just cannot be. That is why I love wearing thongs for those occasions, and sometimes when I just feel like wearing something flirty.” Celestia grabbed Luna by the wrist and pulled her towards the dressing rooms. “Come, you must try them on at once!” Using her magic, she whipped open the closest door and led her sister inside the rather small room. “Here, let me hold them for you while you undress,” she said, locking the door behind them.

“Um... you want to give me some privacy?” Luna asked with a smirk.

“And miss out on the chance of seeing my sister naked yet again? I think not!” Celestia scoffed as she ruffled her wings. “So what are you waiting for? It is not like I have never seen you naked, after all. We sleep naked together most nights anyways.”

“That is a fair point.” Luna blushed as she pulled the sundress from her slim body. Her perky breasts popped out from underneath the hem of the dress, the cold air of the store making her nipples perk up. She glanced to the side as she placed her dress down on the tiny bench.

Celestia spotted her chance. With her heart beating rapidly in her chest, she leaned in and wrapped her lips around Luna’s left nipple, softly lapping at it with her tongue while she massaged and groped her other breast. She heard Luna gasp softly, almost as if she hadn’t expected her to do this.

“S-Sister, we’re in public!” Luna hissed out, her body already reacting to her sister’s loving tongue. A slight tremor slithered down her legs from her core.

“Yes, and that is what makes it all the more exciting...” Celestia murmured, flicking her eyes up to meet Luna’s gaze. She cupped her sister’s folds in the palm of her hand and firmly pressed against it, grinding the base of her palm against her clitoris. “Do you wish for me to stop?” she asked with a smirk. “Oh, you are already getting wet?” She faked a gasp as she straightened up, holding up her wet fingers that glistened with her sister’s arousal. “And in public, no less!” Celestia’s smirk deepened. “I think you like me touching you here... Is this true?”

Luna blushed furiously as she licked her lips, then after a few seconds, she reluctantly nodded. “Didn’t we come in here to try on cute undies?”

“Why, yes! I almost forgot!” Celestia whipped out the thong and held it down low for Luna to step into. Her sister threaded her legs inside the holes and let Celestia slide it up her legs. “Hm... it would not be very sanitary if we did not buy these panties after you tried them on...” She got down on her hands and knees, the thong halfway up Luna’s thighs. “And you are much too wet down here!” she said, making her sister’s blush deepen. “I shall fix that for you at once!”

“What do you... Oh.” Luna’s eyes fluttered, her ears flicked back, and her knees buckled. She bit her bottom lip hard as she stifled a moan, for her sister’s tongue was lovingly lapping at her slit. “Celestia...” she whispered, her hands finding the back of her sister’s head. She pushed it deeper, keeping her from pulling away.

“There we go... All dry!” Celestia chirped as she sat back with a satisfied grin on her face, using her magic to remove her sister’s hands from her head. “Well, mostly.” A thick bead of Luna’s arousal grew between her swollen and puffy labia, then dripped down onto her outstretched finger, which she quickly stuck in her mouth as she gazed up into her sister’s eyes. “Sweet as always.”

Luna flicked her tail, crossed her arms under her breasts, and humphed. “Y-You’re just saying that.”

Celestia’s eyes widened as she stood up. “Sister...” she said breathlessly. “Have you not tasted yourself?”

“N-No,” Luna said, glancing away as she tucked a few stray bits of her mane behind her ever-flicking right ear.

“You want to?” she asked with a devilish grin.

“...Kinda,” Luna admitted with a blush. She pulled the thong the rest of the way up, fidgeting a bit as it slid in between her butt cheeks. Luna twirled her hips, then took a few steps in place as the slim garment settled into its proper place. “You definitely weren’t lying... These are pretty comfy! Not sure if I’m a huge fan of the wedgie bit, but if you say that they’re good...” She slipped a finger down to the back of the thong and tugged it, snugly pulling the fabric up front against her pussy.

Celestia stepped forward with a smirk and pushed her against the wall, her leg grinding against Luna’s throbbing mound and spreading her juices around.

“Geez, when was the last time you had an orgasm? You’re acting kinda needy today,” Luna softly groaned as she laid her head on her sister’s shoulder, using it for support. She felt Celestia’s fingers slip down in between her legs a moment before two of them slipped inside of her pussy. She clenched down on them out of instinct, but made herself relax. Her eyes drifted shut as her sister worked her digits deeper inside of her. She wrapped her arms around Celestia’s back and held onto her, her wings starting to unfurl by themselves as her sister’s lovely fingers danced around. “Here,” she heard her whisper. Luna blinked a few times as Celestia pulled her fingers out of her, her vision slowly focusing on her sopping wet fingers. Her eyes flicked between Celestia’s eyes and her fingers, then she slowly opened her mouth.

“Good girl...” Celestia whispered right before she nibbled on her sister’s earlobe. She pushed her fingers past her sister’s lips and massaged her breasts with her other hand. “See how sweet you taste, how utterly delectable, and... naughty it is to take pleasure from tasting one’s juices?”

Luna felt a shiver run down her back, even though her mound was radiating heat like an out of control wildfire. She licked her sister’s fingers clean, her arousal mixing in with her saliva to yield a thick, yet utterly sweet mixture of liquid that so promptly swallowed. While she would never admit it to anyone other than her sister, she absolutely yearned for more.

Celestia chuckled. “I can tell from the look on your face that you like tasting yourself as much as I do, so... What do you think about this thong? Yay or nay?”

Luna took a few moments to catch her breath adn sat down on the bench, forgetting that she had placed her dress on there only moments ago. “It’s nice, but...” She glanced to the side and bit her lip, her shoulders slumping as she crossed her legs, squirming in her seat.

“What is it?”

“You know you can’t just tease a girl and leave her wanting more!” Luna grinned as an idea popped into her mind. She lit her horn and focused her magic on Celestia’s crotch, a bright light enveloping her pussy. As the light faded away, her eyes lit up with glee. “Perfect!”

Celestia looked down, feeling something warm and throbbing brush against her inner thighs. “You didn’t...” she said, noticing a thick cock dangling between her legs. She grabbed her new cock with her right hand and stroked it, rubbing her new tip with her fingers as a naughty grin grew on her face.

“I did!” Luna said with a squee, clapping her hands together. She stood up and bent over, spreading her cheeks wide to expose the thong. “When we’re done, I think we’re going to have to buy these panties and have this changing room be professionally cleaned.”

“Oh, with the way things are heading, we’re going to have to have you try on a lot more than just one pair of undies...”