Bi(g) Brother Best Friend Forever

"You want me to put a what on you!?" Cadence gasped as her husband stood before her and gave her a foalish pout. "Shining, where are you getting all these ideas!?"

"Uhhh, books." Shining replied, obviously lying.

"Books about pet play?"

"Totally."

"Where is this sudden love of being treated like a lesser being coming from?"

Cadence asked the latter question quizzically with a cocked eyebrow as she looked Shining Armor directly in the eye. Something fishy has been going on and for whatever reason, her husband has completely switched bedroom roles with her. Not that she disliked being the one to call the shots for once. She could completely shrug it off as simply needing some new spice in the bedroom if it weren't for the clues she had found before. The shifty behavior, the two champagne glasses, the thick male hair in the bed and most recently, stains of cum that originated from a mystery stallion.

She had to find out, and until then, the very idea of her husband running around behind her back was putting her in any mood but a loving one. Until she found the truth, she was upset at the possibility but she couldn't let him know that she was onto him. Sure, slapping a leash on Shining and leading him around the bedroom like a pet certainly appealed to her, but she almost didn't even want to look at him. She was so sure that he was up to something that would break her heart once she found out.

"I'm not in the mood, okay?" Cadence deadpanned with a scowl.

"Oh." Shining Armor said, his ears drooping in disappointment. "O-okay, babe."

Days where one was raring to go but the other wasn't were nothing new to the couple but the way Cadence shut him down was quite out of the ordinary. The scowl caught Shining Armor off guard as well as the venomous tone. He couldn't quite put a hoof on what the problem could be. Had the idea of pet play offended her? Perhaps there was nothing more to it than she simply didn't feel like it. But why did she act borderline angry? Nevertheless, Shining Armor felt that it best that he just let it go for now.

Cadence on the other hoof wasn't about to let anything go. Her husband has been keeping something from her and she needed to get to the bottom of it. To do that, she needed to start with the closest pony to Shining Armor save for herself. Later that night, while Shining Armor slept soundly and ultimately lonely and unsatisfied, Cadence, after chugging some coffee to keep herself awake for a trip prepared for just that. It was a cool night with no wind to speak of, perfect for taking a late night flight.

With a pair of bug goggles, a saddle bag full of some bottled water and more coffee, the alicorn Princess jumped out of a window and took off to the South. With her horn aglow and lighting her way, Cadence made her way out of the Crystal Empire and down to Equestria. As if setting her flight on autopilot, she swiftly made her way past Manehattan and before much longer, zipped past Canterlot. She would normally have taken the train but as a public figure, she was sure to spotted and for the sake of her investigation, she couldn't take such a risk.

At the speed of which she was travelling, her destination was now in sight after wiping more splattered bugs from her goggles and she could finally make her landing upon the highest building in Ponyville. She would have to approach delicately at this hour as everypony would surely be asleep and firmly planted within the realm of dreams, having tea parties with her Aunty Luna. Instead of knocking on the front door, she swooped down and landed herself on the highest balcony. Finally being able to rest her tired wings from the long flight, Cadence wiped a bead of sweat from her brow, down a bottle of water and carefully trotted inside.

As expected, the hallways of Twilight Sparkle's crystal castle were dimly lit by the occasional candle on the walls and nothing else. Cadence felt that it would be rather bothersome of her to wake her slumbering sister in law but desperate times called for desperate measures. Slowly and carefully, Cadence crept down the hallway towards the bedroom of the smaller purple alicorn when suddenly, a door clicked open just behind where she stood.

Turning around, Cadence came face to face with none other than the newly winged Spike accompanied by an unfamiliar orange scaled dragoness with hot pink scaled upon her head and back, about twice the height of her male, purple counterpart. Upon further observation, it appeared that the reptilian duo was sneaking into Spike's bedroom while holding claws. Both dragons appeared to be doing the same thing Cadence was trying to do and but both parties managed to end up being detected by one another. Surely there would be some form of mutual understanding.

"Uhh, I won't tell if you don't." A blushing spiked said as his female companion too took on a new shade of red.

"Of course, Spike." Cadence replied with a smile and a nod. "Here, take this."

Being the Princess of love, Cadence always had a supply of rubbers to hoof out to whomever may need one. With that, Spike and apparently his date for the evening retreated into the former's bedroom and left Cadence to continue down the hallway in search of her husband's sister. Before long, Cadence found herself slithering through the door and sneaking up to the bed of her sister in law and best friend. At this point, she decided to Tartarus with being sneaky as she was about to wake her up anyway.

She felt bad by doing so but it needed to be done and she needed the closure in the form of some questions answered. As the lavender alicorn snored, Cadence gently placed a hoof on her shoulder to coax her out of her sleep. Twilight was always a heavy and not to mention noisy sleeper so some more persuasion may be needed.

"Spiiike, I told you not to stay out so late." Twilight blurted out, still sound asleep.

"Twilight, it's me." Cadence whispered.

"You better wrap it up, bucko, we can't have Smolder laying any eggs."

"What the...oh, that's a cute name. Uh, Twilight, can we talk?"

"Huhhh...cuppa Irish tea..."

"What?"

"Huh?"

"Oh for the love of...Twilight, there's a book burning festival in the town square!!"

"I'll kill them!!"

Just like that, Twilight Sparkle sprang awake ready to tear somepony who would dare damage a book limb from limb. Instead of seeing a mob of ponies tossing books into a flaming heap however, she was face to face with her sister in law who should be snickering at the joke but instead sported the look of pure worry.

"Cadence?" An immensely confused Twilight said as she looked around to see no such atrocities taking place. "What the hay are you doing here?"

"Twilight, I'm so sorry I had to come here and wake you up at this hour but I didn't know what else to do. I need your help."

"W-what's wrong? Oh h-hang on, let's go into the library to talk, okay?"

Twilight knew that if Cadence left her home this late at night to urgently seek conversation with her, then whatever problem Cadence must be experiencing is indeed a serious one. After leading an exhausted and stressed out Cadence to a nice, comfy chair in the library, she quickly retreated to the next floor down to brew some tea for her guest whom just spent hours flying through the cool, buggy skies. As quickly as she left, the younger Princess returned with a piping hot pot of tea and two mugs.

After a quick visual scan to ensure that every one of her precious books were still in place and free of any damage of the pyro variety, she calmly trotted over to her sister in law whilst practicing the breathing exercise she taught her. Once two cups of tea were poured and one hoofed over to the elder of the two, Twilight took a seat of her own across from Cadence and resumed the conversation.

"Cadence, what's troubling you?" A concerned Twilight asked in a comforting tone.

"Twilight, I didn't know who else to turn to." Cadence replied, nearly on the verge of tears. "I'm just going to come out with it."

"What is it?"

Twilight then began sipping her tea.

"Twilight...I think Shining Armor might be cheating on me."

"Pffft!" Twilight spat out her tea at the bombshell that was just dropped upon her. "What!?"

"I've found some clues around the palace and he's been acting so off lately. Twilight, I almost don't even know him right now."

Twilight Sparkle's jaw hung wide open and hot tea covered her flank and chest as she lay on her side. To think that Shining Armor, her big brother best friend forever could do such a thing and betray his beloved both rendered her speechless and made her blood boil. Still, they were simply allegations at this point and she was unaware of any proof that may or may not have existed. After taking a moment to calm down, she regained her composure and began wiping up the tea from her body with a nearby cloth as she attempted to resume the conversation.

"Okay..." Twilight said in between breaths. "Cadence, tell me what kinds of clues you've found."

"I came home a few weeks ago and found him taking a bath. There were two used champagne glasses on the side of the tub."

"Okay, go on."

"He keeps disappearing to hang out with some new friend of his and acts like a colt with his hoof in a cookie jar whenever I ask him about it."

"Okay? And?"

"I found a hair from another pony in our bed!"

"No...please tell me he...he wouldn't."

"I don't know anymore, Twilight!"

Cadence, being borderline distraught, couldn't quite think clearly enough to promptly tell Twilight the last of the clues she found and ask an important question that she had on her mind the entire way over. At this point, Twilight was pacing back and forth around the library furniture, her free hoof tapping her chin while in deep thought. She knew something that unbeknownst to her, Cadence did not but would find out shortly.

"He could never...unless..." Twilight said to herself.

"Unless what?" Cadence asked.

"Well, you know."

"No, I don't know. Look, Twilight, I know this may sound silly, but I need to ask you."

"Ask me what?" Twilight again began to sip her tea.

"Has your brother ever had any bisexual tendencies that you know of?"

"Pffft! He never told you!?"

"So he's bi!?"

"Of course he is!"

"Why didn't he tell me!?"

"Because he a damned fool, that's why!"

Cadence's emotions were quite the mixed bag. She was shocked but at the same time, her suspicions confirmed that her husband has been sleeping with another male when she was out. Though she felt hurt that Shining Armor failed to confide in her something very important regarding his sexuality yet relieved to find that he had not found another mare to pick up what she left behind. To say Cadence was immensely confused would be a massive understatement.

"It all makes sense now!" Cadence beamed as she shed tears of relief. "So he's not seeing another mare because I can't fully satisfy him! He's sleeping with another guy because he needs some cock that I don't have!"

"That's...one way of putting it." Twilight Sparkle deadpanned. "It still doesn't excuse him for not telling you! You're his wife! He should be able to tell you anything!"

"You're right, and I'll be having words with him about that. Oh Faust, Twilight, I'm just so glad that it wasn't something I failed him on...well, I failed to have a dick but that's besides that point!"

"So, how would you have felt about it had he actually told you?"

"I would never ask him to sacrifice his needs like that for me! I would have been fine with it if he found a guy friend to fool around with!"

"My point exactly. If he would have just told you that he likes mares and stallions, that would have saved you a lot of stress. The big, dumb idiot."

Cadence had some of the most important questions answered yet still had so many more she needed to ask. For the most part, all she cared about was that whatever her husband has been up to wasn't her fault nor was it going to be a dealbreaker for their relationship. She still wanted to know how long Shining Armor's family knew, when his first experience with another male was and the like. Some questions, Twilight Sparkle had the answer for, others not. There was only one way to find out and it was near dawn. Neither Twilight Nor Cadence had slept a wink so after a warm, sisterly hug, the latter spread her wings and flew home as quickly as she could.

As far as Cadence was concerned, every last one of her plans, appointments, and meetings not directly involving spending time with her husband to discuss her recent discovery were hereby cancelled. She hadn't slept since the night before, she was simply exhausted, needed this day for herself and her husband, and nopony was going to tell her otherwise. Once she returned home, she would march right up to her husband, cancel his plans as well and have themselves a heart to heart.

At least, that's what she had hoped. As she landed at the entrance to the Crystal Palace and trotted past several of her immensely confused guards, she rehearsed her opening to the impending conversation with her beloved. She still wasn't sure whether she should go in with an angry demeanor or a soft and understanding one. Princess Mi Amore Cadenza trotted up the steps to her and her husband's own quarters with intent on getting to the bottom of things. She was about to find out however that in her absence, somepony had beaten her to Shining Armor's bottom. As Cadence slowly approached their bedroom, she could make out two male voices conversing on the opposite side of the door.

"I don't know how much longer we can keep this up before she finds out." Shining Armor said as Cadence observed him worriedly pacing back and forth through the keyhole on the door. "Aw fuck, I feel terrible saying that, like I have to keep a secret from her."

"I've been trying to tell you this the whole time, Shining." A familiar yellow stallion said as he sat upon the bed, trying to be supportive. "You should tell her that you're bi. You need to put more trust in her that she'll understand."

"I'm scared, dude, I'm really fucking scared!"

"I've seen that guy before..." Cadence thought to herself as she continued to watch through the keyhole.

"What if she leaves me!?" Shining continued.

"No, baby, I'd never do that."

"No, she wouldn't do that!" Heart Flutter countered. "Not because you are who you are!"

"What am I gonna do!? Ohh, fuck, I wish I was straight so this never would have happened!"

Heart flutter then hopped off the bed and rushed over to his distraught friend to comfort him.

"Shining, buddy, get a grip!" Heart Flutter said as he grabbed Shining Armor's head and held him directly in front of his face. "Listen to me! You can do this! You have to do this! I'll be with you every step of the way! I promise it'll work out."

"I'm scared." Shining Armor sobbed. "Oh gawhawhawd I'm scared."

Heart Flutter then threw his arms around Shining Armor's neck and brought him in for a warm, supportive hug.

"Shh shh shhh, it's going to be fine Shiney." Heart Flutter whispered in his distressed friend's ear. "You've been there for me, I'm here for you."

Finally, the sudden realization as to who this mystery stallion was popped into Cadence's head. She remembered Heart Flutter as that effeminate looking stallion whom she caught checking out her husband's ass at the fair. Then she remembered how immediately afterwards, Shining Armor made some sort of excuse to leave, apparently having gone off to follow his opportunity at finding male companionship. All the events of the past several weeks were now clicking into place. Everything made sense now.

Having failed to quell Shining Armor's weeping, Heart Flutter took a new approach and began planting soft kisses on Shining Armor's neck. Now that he had more of His attention, Heart Flutter could reassure his special friend that everything was going to be just fine. Unbeknownst to both of them however, the mare on the other side of the door whom of which they were unaware of was finding her interest piqued by watching her husband be covered in kisses by another stallion. Something that she wanted to see more of for some reason.

"Feel better?" Heart Flutter asked as he held Shining Armor close.

"Mhmm." Shining Armor cooed as he began returning kisses. "Heartsy?"

"Yeah, Shiney?"

"Will you please fuck me? I really need this."

"Aww, of course I will...but next time, you're doing the grunt work. I get that you like being dominated but remember, I like it in the ass too."

"Okay."

Cadence's tail suddenly rose up as she watched her husband bending over the bed while the other stallion mounted him and slowly inserted his cock into him. Part of her wanted to intervene but on the other hoof, that would cause the two horny stallions to stop what they were doing and she couldn't deny that she wouldn't want that to happen. Heart Flutter held his partner close as he gently pushed in and pulled out of him while whispering sweet nothings in his ear.

Much to Cadence's dismay, she found herself burning in her nether regions and growing wetter every second she secretly watched this other stallion plow her husband from behind. If there was one thing she could never have predicted, it was getting off to such a sight. She couldn't just neglect herself and allow her burning, winking marehood to go untouched. As she continued to peek in on the two stallions, she slowly reached a hoof down to her privates and bit her lower lip once she made contact.

The sight and sounds of a big, wet dick being slid in and out of her husband's bum coupled with the passionate moaning from both him and the stallion on the giving end were sending her pussy into a frenzy that only the most rigorous of rubbings could curb. Cadence was full on masturbating as she secretly watched the two male ponies in front of her going at it and she was loving every second of it. Try as she might, she couldn't help but let out a few excited yelps and moans of pure pleasure herself, but much to her fortune, the two stallions were too caught up with each other to hear.

Cadence was now soaking the floor beneath her as she passionately rubbed herself and she neared a peak of sorts that was previously unknown to her. She had many a wonderful sexual encounter with her beloved husband but nothing had gotten her going quite like what she was bearing witness to. At last, Heart Flutter blew his load in and all over Shining Armor's firm butt and at the same time, Cadence struggled to keep herself quiet as she too experienced an orgasm like never before. Suddenly, having a talk with Shining Armor and telling him that she knew about his preferences wasn't so high on her list of priorities.

"Oowow." Cadence moaned as she came down from her pleasure high. "I have got to keep these two going at it."