Since the day of their 'bonding experience' in the hot tub weeks ago, the two royal sisters started to become even closer with each other thanks to their forbidden romance. They exchange kisses, went on dates and engaged in intimate relations with each other, all in complete secrecy of course.

Both of them silently agreed to act like regular sisters around their friends and mothers, then act like two sickeningly sweet sweethearts once they were alone.

Despite believing that they were doing a good job keeping things between them low-key and private, one by one their friends started to suspect that something weird was going on between the two, but were never completely sure.

One instance was when Sunny was about to pass by the bathroom when the door opened and Zipp and Pipp walked out with towels around their heads and lower bodies.

"Pipp, are you sure you didn't drop that soap bar on purpose?" Zipp inquired suggestively with a raised brow.

The younger princess giggled and lightly nudged her sister. "And what if I did? You know you enjoyed the view."

Zipp chuckled as well. "You are one dirty little filly."

"Says you." Pipp responded while leaning against her sister.

"Oh yeah?" Zipp challenged as she leaned back.

"Zipp!" Pipp laughed.

The two Pegasi continued to laugh and playfully push each other around as they walked away, oblivious to a blushing Sunny watching them.

"Ok…" Sunny responded, completely weirded out and still keeping her eye on her two departing friends as she walked away herself.

Another instance was when Hitch came to have breakfast with them and he saw the two sisters sitting across from each other, giggling and laughing.

Normally this wouldn't be unusual, but what was odd was how Pipp stared at Zipp as she talked. While her chin rested on top of her hooves, her eyes were half-open and filled with adoration. Then, Zipp took a spoonful of cream from her bowl and held it out to Pipp.

"Ok Pipp, open up and say 'Aaah!'" Zipp encouraged her sister playfully.

Pipp opened her mouth wide. "Aah!" she said before closing her mouth around the spoon. Zipp gently pulled it out and when the two shared a laugh and blushed together when Zipp put the spoon in her own mouth.

Hitch blushed when he realized what just happened and stared at them with wide eyes, even as he ate his own cereal. Eventually, the sisters felt his eyes on them and turned to him.

"What?" They both asked.

Hitch quickly snapped out of his trance and his eyes darted around rapidly. "Nothing! Nothing!" he said quickly before immediately eating the rest of his cereal. As he began to leave, bits of cereal flew out of his mouth as he talked. "Well, gotta go, got some… Sheriffing to do…"

The girls watched Hitch go with raised before turning to each other and shrugging. Both quickly went back to feeding each other breakfast and getting lost in each other's eyes.

The third instance occurred when they were watching a romantic comedy together with Izzy. They laughed and cried together, and during nearly every romantic scene, Zipp faked a yawn and put her hoof around Pipp, while Pipp leaned her head against Zipp's shoulder.

Izzy didn't think much of it due to being so into the movie, and also because she was doing the same trick to artificial unicorn friend; Señor Butterscotch.

What did get her attention was, just after Zipp got up to get more popcorn, Pipp gained a cheeky grin and quickly smacked Zipp's butt with one of her fluffy wings, surprising her as well as Zipp.

Zipp glanced back at her sister with a grin that said 'I'm gonna get you back for that' before leaving. Izzy glanced at the two with a raised brow and a deeply confused expression.

After Zipp came back with the popcorn and sat down next to Pipp, she smirked as she subtly unfolded one of her wings and lowered it down to brush Pipp's flank with her feathers. Pipp jumped and squeaked at the sensation, surprising Izzy as well. When Pipp turned to Zipp, her older sister/secret girlfriend looked away and innocently whistled. Pipp just shook her head with a knowing smirk.

Izzy leaned over to Señor Butterscotch and whispered. "I wonder what's going on with Pipp and Zipp. Those two are being super sneaksy," she remarked. She paused before gasping softly. "What?! No! Pipp and Zipp aren't a thing… right?"

The unsure unicorn glanced at her pegasi friends as they playfully threw popcorn at each other.

The next day, the two sisters got up early to get ready for another one of their secret dates. After they made lunch together, Pipp gave herself a hooficure and applied some makeup to herself and left the Brighthouse. Zipp agreed to wait ten minutes before meeting her at the spot they agreed to meet at, it was supposed to be a date after all.

Zipp waited, watched the clock and when ten minutes had passed, she quickly got up and headed to the door.

Just before she could step out, something started ringing and with a sigh she took out her phone. Queen Haven, her and Pipp's mother, appeared on the screen.

"Hello Zephyrina! Oh! Sorry. I mean Zipp." Queen Haven said warmly.

"Hi Mom, how you doing?" Zipp inquired.

"Oh, just fine, busy as ever as you can probably guess" Queen Haven replied. "And how about you, dear? Enjoying your life as a detective with your friends?"

"Sure am. Just about to head out." Zipp admitted.

"Oh? With one of your friends?" Her mother inquired.

Zipp seemed to freeze up a little upon hearing her mother's question.

"Well…"

"Hm?"

"N-Not… Not exactly…"

"Not exactly?"

"It's… kinda hard to explain, Mom." Zipp confessed awkwardly.

Queen Haven gasps sharply. "I see now… I know exactly what's going on."

"You… do?" Zipp asked, nervously. She knew there was no way her mother could've found out about her and Zipp, they had done everything they could to keep up a friendly facade in public. But still, parts of her worried about their occasional slip ups, if they were enough to rouse ponies suspicions. She didn't think they made any around their mother, but the way her mother spoke made her think otherwise.

"Yes! You're going on a date!" Queen Haven exclaimed excitedly.

"Uh…" That was all Zipp could say. While her mother wasn't entirely wrong and didn't seem to suspect anything, this was a conversation she'd never been excited about having with her mother someday.

"Oh, I'm so happy for you! My oldest daughter is finally going on her first date!" Queen Haven gushed.

"Mom…" Zipp muttered, embarrassed.

"Please, tell me everything!" Queen Haven demanded eagerly. "Who is this very special somepony of yours? Who is this lucky stallion? Or mare. Whatever way you lean. I was never really sure…"

"Mom! Ew! It's not a date! Just hanging out with a new friend, that's all." Zipp stressed.

"Oh, come now, dear. There's no need to be shy. You can tell me if you're seeing somepony." The queen encouraged her daughter. "Whoever it was must be special if they've caught your attention. It must be almost overwhelming for you. Believe me, I know. When I was young and in love, I…"

"Oops! Sorry, Mom! Gotta go! Bye!" Zipp said quickly before hanging up, opening the doors and flying away at super speed.

Later, in Maretime Bay, Zipp had just made it to the table Pipp was seated at with smoothies set in front of their seats, in the center was the lunch the two of them made. To any ponies that saw them, it was just like two sisters having lunch together, completely normal and not obscene in any way. Of course, Pipp and Zipp knew differently.

"Hey, sorry I'm late." Zipp said upon arrival. "Have you been waiting long?"

"Oh, not long." Pipp replied while occasionally scrolling through her phone. She set it down when she noticed Zipp raising a brow at her. "Sorry… Ok, maybe a little long…"

"Sorry. I was about to leave and Mom called and well… You know how she is." Zipp explained.

"Oh, how is she?" Pipp wondered with interest.

"She's… Mom. Busy and all that. She actually thought I was going out with somepony…" Zipp admitted, rubbing the back of her head.

"You are." Pipp stated matter-of-factly.

"I couldn't tell her it was you, obviously." Zipp reminded her.

"Mom's not as absent minded as you think she is, Zipp." Pipp warned her older sister.

"I never said she was…!" Zipp tried to defend herself before sighing. "Sorry… Keeping this a secret from her has been harder than I thought…"

"It's ok, believe me, I get it." Pipp sympathized. "It's been hard lying to our friends… But we know we don't have a choice. As much as we love each other… us being together is wrong. And if Mom asks me face-to-face if I'm seeing anypony behind the scenes, I don't know if I'll be able to lie to her…"

"Me neither… But she didn't seem to suspect anything when I talked to her." Zipp reasoned.

"Maybe she does but doesn't wanna face the possibility of her daughters…" Pipp began worriedly.

"Hey, if she doesn't wanna believe it, then she won't." Zipp said.

"I don't know if it's that simple, Zipp…" Pipp muttered, still concerned.

"Hey, come on, relax. Let's just enjoy our lunch like two normal sisters would." Zipp suggested.

Pipp inhaled and exhaled deeply. "Yeah, ok," she smiled.

"And when nopony's looking… I'll move one of my hindlegs under the table closer to you and then rub your…" Zipp started to say in a suggestive tone.

"Zipp!" Pipp exclaimed in embarrassment.

"I'm kidding!" Zipp chuckled.

"Just eat your lunch. I worked, like, super hard on it, you know." Pipp huffed, cheeks still red.

"Yes, dear." Zipp teased, which made Pipp giggle a little before they both started eating.

Unbeknownst to either of them, the two were being watched by somepony using a pair of binoculars made out of empty glasses, binoculars that were poking out of a far off trashcan. The makeshift binoculars slip back into the trash can that quickly hopped closer to the two before stopping. The binoculars pop out again and are revealed to be held by Izzy.

Señor Butterscotch, via Izzy's magic, rose up behind her, with a pair of binoculars that Izzy most definitely made, attached to him.

Izzy took notes as she watched Zipp and Pipp eat, laugh and flirt with each other from a far.

"Hmm… Interesting…" Izzy mused. She glanced up at Señor Butterscotch and tried to sound as professional as possible. "What do you think, Señor Butterscotch?"

The artificial unicorn's head moved up and down a little as it floated.

"Hmm, yes, their sparkle's are super shiny and bright. That means love is in the air." Izzy realized before sniffing around. "And it smells like cupcakes! With a hint of trash… Course that last bit is probably from the trash can I'm in. I better head back and tell Sunny about the smell! Of love, not trash this time though."

Izzy lowered herself back into the trash can just before Señor Butterscotch dropped down into it and the lid covered them up. The trash can tilted over onto its side and rolled off, much to the alarment of other ponies. Posey was unlucky enough to wind up in the way of the trash can and screamed as she ran off while the can seemed to chase after her.

Zipp and Pipp turned when they heard the scream but shrugged soon after and finished their meals.

"Ok, now I'm gonna take you to some place I know you'll love." Zipp declared as she got off her seat, along with her sister/girlfriend.

"Ooh! Is it another movie?" Pipp inquired with interest as she started to follow Zipp.

"Nope!"

"Karaoke?"

"Try again."

"Oh! Oh! That creepy haunted house we went to on Nightmare Night?"

"Better than that!"

Later on, Zipp guided Pipp through the beach, which she briefly thought was the 'special place' Zipp wanted to take her to before Zipp told her to close her eyes and follow her voice. Trusting her sister/girlfriend, Pipp did so. Even when Zipp told her to stop and fly down into something

"Almost there, Pipp. Almost there." Zipp urged her sister/girlfriend.

"Zipp…" Pipp whined a little.

"Patience little sis, and no peeking." Zipp reminded her.

Pipp giggled. "I'm not!" she insisted. "Just tell me that we're there."

"Ok… Stop." Zipp said before Pipp stopped in her tracks. "Now… Open them."

Pipp did so and gasped when she gazed around them and saw the glowing crystals and strings hanging from the ceiling of a familiar cave.

The older sister moved to one side of a small pond inside the cave while her sister/girlfriend stayed on the other, still in shock. "Ta-da!" Zipp said. "Look familiar?"

"Yeah… It's the same cave we got trapped in during Portrait Day." Pipp recalled.

"Yep, this is it. But with a way in and out this time." Zipp said as she gestured to the hole in the ceiling that they used to get out last time.

"Right. So… Not that I'm complaining or anything, but… Why did you bring us back here?" Pipp inquired. "We, like, had a major fight in here last time."

"And made up when we sang our song for Portrait Day too." Zipp reminded her. "It's also completely private, which means… It's the perfect place for…"

"Sexy time?" Pipp inquired eagerly as she wiggled her rump with a cheeky grin.

"I woulda preferred 'made love', but sure." Zipp shrugged with a smile.

"Wow Zipp, what made you think of this?" Pipp wondered as she looked around.

"Well, ever since we started this relationship, you sometimes complain about how few places there are to do l what we did in the spa again." Zipp reasoned.

"I-I-I don't complain that much…" Pipp tried to insist as she smiled in embarrassment.

"But now, we have a place where we can be totally alone. Where we can make out and make love without being seen or worried about being seen." Zipp said.

"That does sound great." Pipp smiled.

"So…?" Zipp asked expectantly. "What do you say?"

"I say…" Pipp began before putting on a come-hither look. "Let's break this place in, lover."

Zipp flashed her sister/girlfriend a flirtatious smile before she and her walked closer to each other.

Once they were face-to-face, they cupped each other's faces and kissed. The two played patty cake with their tongues as they kissed and swapped spit. Their tongues soon started swirling around each other and took turns sucking each other's tongues. When they separated, they created a long string of saliva between them.

Zipp moved her head to blow into sister's ear, making Pipp shiver.

Smirking, Pipp quickly turned around, lightly batting her sister in the face with her tail, before taking a few steps forward before lowering her head to the ground and raising her rear with a playful wiggle.

Zipp gained a big smile on her face as blushed and licked her lips. Her wings slowly rose up and became erect as she came closer and closer to her sister/girlfriend.

Pipp gasped the second Zipp started to slowly lick her hindquarters all over, moaning loudly as she did so.

"More… Lick my butt more…! Like my butt…!" Pipp exclaimed with a big smile on her face shortly before Zipp pressed her muzzle against the space between her sister's legs. Pipp moaned even louder as her sister licked the deepest parts of her ass

Zipp followed up on this by standing on her hind legs, placing her hooves on her sister/girlfriend's flanks, then slamming her crotch against her sister's thoroughly licked bottom.

Pipp squeaked and cooed as her big sister started rutting her like a stallion, despite not having the proper equipment. The sensation of her sister's crotch repeatedly smacking against her own was something she had never experienced before. The slapping sounds their bodies made echoed throughout the cave, as did their moans and cries.

The pink Pegasus rose up as she let out a longer cry, which made Zipp move her hooves from her sister's flank down to her back before wrapping them around her barrel as she laid on top of her. Soon enough, the royal sisters were one hot, sweaty and bucking mass.

Zipp occasionally licked the back of her little sister's neck to make her tremble with pleasure even more. She even made a high pitched squeal when Zipp gently bit her ear tips. Along with the sounds both mares were making, the whole cave was also filled with the scent of their combined sweat and saliva.

"Oh Zipp… Please… Don't tease me…!" Pipp moaned.

Zipp smirked as she lifted herself up. "Oh yeah?" she asked before she moved off of Pipp, causing her sister/girlfriend to gasp in dismay. Zipp planted her haunches down on the ground behind Pipp and kept both her hooves on the pink Pegasus' flanks. "Well, would you prefer it if I did… this?"

Zipp raised a hoof and brought it down on Pipp's bottom, hard and fast.

The spank made Pipp squeal in pain and arousement. It also left a red hoofprint on Pipp's tushie that quickly starts to fade until Zipp spanks her again.

"Ooh! Zipp!" Pipp remarked with a smile, looking both aroused and interested. She squeaked after another quick spank from Zipp. "Is that the best you got? Come on, sis."

Zipp obliged by spanking her sister/girlfriend harder and faster, over and over she brings her hoof down on her rump. Her tail raised and out of the way, Pipp moaned and gasped with pleasure as the surprising exciting spanking continued. Each spank sent a shiver through her entire body and made her weak again in the knees as well.

With an excited smirk of her own, Zipp tried to savor the intense rush she felt in disciplining her girlfriend. Every time her hoof hit one of Pipp's butt cheeks, the red hoofmark she left on it grew redder and more visible. Unlike the first time, it didn't fade away quickly and remained on her hindquarters.

"Hmm… Spank me, I've been naughty!" Pipp encouraged, which made Zipp bring her hoof down harder. "Mmm… Wish we had a whip of some kind… ooh! That'd be extra fun!"

After one more spank, one that's bound to leave a bruise, Zipp stood back on all fours. She turned around, wrapped her tail around Pipp's, then moved forward a bit before coming back and slamming her bottom against Pipp's.

"Oh!" Pipp said in surprise before she quickly got the idea as she moved forward as much as she could, as did Zipp.

They stopped when their tails became taut, then moved back in unison to slam their butts together. Shortly after, they pressed their rears together, flattening their cheeks and moaning as they rub their heinies against each other. They soon began moving back and forth, bumping and rubbing rumps repeatedly, both moaning and shaking with pleasure.

"Oh Zipp… this is great! I just love how this feels!" Pipp exclaimed in arousement.

"Oh yeah… Me too!" Zipp added, just as hot and bothered as her sister/lover.

"Zipp! Zipp! I'm gonna… I'm about to…!" Pipp panted feverishly.

"Oh yeah… Me too!" Zipp agreed.

The two sisters slam their butts together one more time before screaming at the top of their lungs. If anypony were near the hole they came through, they DEFINITELY would have heard them.

Shortly after, the two let go of each other's tails then fell over onto their sides, both out of breath and sweaty. It took a great deal of effort, but they managed to slowly turn themselves around so that they were looking directly into each other's faces.

"Oh… OMG… you really are the brains of the group, Zipp…" Pipp remarked, completely blown away.

"Nah… I mean I improvised a little… But mostly I got the idea from some of Mom's books." Zipp confessed.

"Wait, Mom? You got that from one of Mom's books?" Pipp asked in shock.

"Yeah, I couldn't believe it either…" Zipp admitted. "Guess being a pervert runs in the family…"

"Maybe. Then maybe…" Pipp began to say.

"We can't, Pipp" The older sister cut in.

"But…"

"We can't tell anypony. They wouldn't understand. Nopony would."

"Yeah… I know."

"Hey. Sorry to bring you down like that."

"No, it's fine. You didn't. Just brought me back to reality, as all." Pipp assured her secret girlfriend.

"It's harsh, but it's true." Zipp said, regretfully.

"Yeah…" The pink pegasus sighed with sadness in her voice

Zipp felt bad for saddening Pipp like this, after all she was now both her sister and her girlfriend, so she wanted nothing more than for her to be happy. However, all the lying, sneaking around and secret keeping had clearly taken its toll, on both of them really. But it seemed to effect Pipp especially hard.

She reached over and put a hoof on Pipp's cheek. "Hey, listen. I know it's hard, but… I want you to know that… Even if something goes wrong and everypony turns on you, I will always be in your corner." The white pegasus expressed to her smiling and teary eyed little sister.

"Thanks, Zipp." Pipp expressed, sweetly. "I love you."

Zipp smiled back. "I love you too."

"Hey. Let's do it again!" Pipp suggested, now completely re-energized. "Like, a bunch more times. Up for it?"

The older sister smirked at her younger sister's high libido. "Sure," she said before they held each other's faces and kissed again, while also intertwining their legs.