Lynn Jr closed her eyes and took a deep breath. "Good...game..." she muttered.
"If it makes you feel any better," Lincoln reassured her, "you didn't loose by much."
"Don't use the L word, Stinkon." She replied.
"Oh, sorry." Lincoln replied when he realized his mistake, "Good game."
He had just beaten her in Guitar Hero: Rage Against the Machine, on the song Pistol Grip Pump.
"Sweet!" Said a voice behind them, "You got Guitar Hero!" It was Luna.
"Yeah," mumbled Lynn, "and Lincoln just beat me..."
"I'm sure you could beat Luna." Said Lincoln.
"Seriously, brah?" Luna scoffed, "I'm the only one in this family that plays musical instruments."
"Yeah," Lincoln replied, "but video games are different."
"Yeah, they're easier." Luna scoffed.
"Alright," Lincoln said as he removed the controller's strap from around his neck, "let's see you beat our scores."
"Let's make a wager out of it." Luna smirked, "If I get a worse score than both of you, I'll do you guy's laundry for a month. If I beat Lynn but not Lincoln, Lynn and I have to do his laundry for a month. If I beat both of you-"
"We do your laundry for a month." Lincoln interrupted.
"No," Luna replied, "you two have to wear each other's swimsuits to my birthday pool party today. No more, no less."
"Alright." Lincoln shrugged as he handed her his controller. He wasn't worried about loosing as there was no way Luna was being serious.
"You're on." Lynn agreed, not worried about loosing as there was no way she could loose to both Lincoln and Luna.
They were bith very wrong.
Luna's beat Lincoln's score by several times the amount he beat Lynn. Lincoln was in disbelief where as Lynn grabbed a cushion from the couch and screamed into it, as her ego was in twice as much pain now.
"See you guys in an hour." Luna said smugly, "And remember, you were each other's swim suits, nothing more."
"Really?" Asked Lincoln.
"It's what you agreed too~." Luna replied as she went into the back yard to finish setting up for the party.
Lincoln gulped.

The Louds had gotten an above ground pool few weeks prior, and while it was nothing fancy, Luna was eager to have her girlfriend, Sam over for a swim, largely for the sake of seeing her in a swimsuit. Her parents had taken all of the Loud kids younger than Lincoln to Dairyland for the day, so it was going to be just her adult siblings, her bandmates and Chunk. And because her parents were away, she could get away with turning a blind eye if anyone under twenty-one wanted to snag a beer.
In addition to the cooler of beer, she set up a table with chips and other food, as well as a cd player blasting some Mick Swagger tunes.
Not long after she changed into her purple bikini, her guests showed up and Luna led them to the back yard where Leni and Luan were already hanging out in bikinis.
Luna went to the bottom of the stairs and called out, "Lincoln! Lynn! Guests are here, time to come mingle.~"
Lincoln and Lynn reluctantly came downstairs. The former was wearing nothing more than a red bikini bottom which contained his
decent sized bulge. The latter was wearing orange swim trunks and a red bikini top. Both of thier faced were as red as Lynn's bikini.
Luna crossed her arms, "Ah, you two are supposed to wear each other's swimsuits, nothing more."
"We are." Said Lincoln.
Luna raised an eyebrow, "You're only wearing half of hers."
Lynn rolled her eyes, "Let me go get a shirt."
"No," said Luna, "you're supposed to wear each other's swimsuits, nothing more."
"Are you fucking shitting me?" Lynn asked.
"That was the bet." Luna answered.
Lynn looked at Lincoln who blushed even harder now.
Lynn let out a frustrated growl before taking off her bikini top and handing it to Lincoln, who proceeded to put it on. He was able to tie the neck strings but was having troble with the lower ones. Luna noticed him struggling so she came over and tied the strings for him. When she finish she reached down and pulled the sides of the bikini bottom inward, into his ass crack before patting him on the bottom. He immediately pulled the bikini bottom outward, and pulled it down so that it would cover the bottoms of his cheeks. He didn't realize this left the top inch and a half of his ass crack showing.
Lynn crossed her arms to cover her chest. It was about as flat as Lincoln's, but she still felt self-conscious about having her nipples exposed.
Luna led her siblings out to the back yard where they were met with laughs and hollars from everyone except Chunk. As soon as he saw them he said, "Holy hell, you actually got them to do it!"
Lincoln couldn't help but grin a little. As embarrassed as he was, it was kind of fun being oogled.
Lyn on the other hand, was not so happy. She wore a scowl on her beet red face. She wasn't just displaying her body, she was also displaying the fact that she lost something. Fortunately it was just those at the party as the Louds had installed a wooden fence around the back yard which added some privacy.
"Lincoln," said Sam, "grab me brewski will you?"
Lincoln walked over to the cooler and reached down to grab a beer. As he did so, he heard cat calls coming from Leni and The Moon Goats. Realizing that they were staring at his ass, he shot back upright and grinned before walikng over and giving Sam the beer.
Seeing the alcohol, Lynn thought some liquid courage would do her some good. Keeping one arm over her chest, she went to the cooler and grabbed a beer, which she then shotgunned.
Leni giggled and called out, "Linky, you should put on some sunscreen."
Seeing as it was a sunny, cloudless day, Lincoln went over to Leni who was holding a bottle of sunscreen.
"Turn around and I'll get your back." Leni ordered.
Lincoln obeyed and Leni squirted some sunscreen onto her hand and began rubbing it on her brother's body.
"You look like you could use some help." Luan said and grabbed bottle from her sister's hand.
Thinking Luan's intent was genuine, Leni said, "Oh, I don't need help, I just wanted an excuse to touch Lincoln."
Luan blushed and muttered, "I know."
It then clicked that Luan's motives were the same as her own. "Oh, well then you can do his front!" Leni replied, "Just be subtle about it."
Luan rolled her eyes and stood in front of Lincoln, staring at his torso, both out of lust and being too embarrassed to look him in the eyes. Linc noticed that she wasn't making eye contact, took a peak at her chest. She had 40DD breasts, so there was a lot of cleavage for him to look at.
"Holy shit, this family's messed up." Sully laughed, "I like it!"
"You know, you should probably put on some sunscreen too Lynn." said Luna.
"No thanks." the tomboy grumbled in reply as she opened another beer.
"What, are you afraid of letting people see your nipples?" Sam teased.
"I ain't afraid of nothin'!" Lynn replied and took a few gulps of beer.
Luna grabbed the bottle of sunscreen from Luan and told Lynn, "Come prove it!"
Lynn scowled before taking another swig of beer, setting the can on the table, and walking over to Luna and Sam. Once she was close enough, Luna squirted some sunscreen onto her chest.
"Ooh, money shot." Sully chuckled.
Lynn glared at him before turning away from everybody and rubbing the sunscreen onto her flat chest and abs.
"Can I have some?" Sam asked held her hand out to Luna, who then squirted a good amount of sunscreen onto her hand. Sam then started rubbing it all over Lynn's back.
"Um, Luan," said Lincoln, "I think you got it all."
Having been distracted by Lynn, Luan looked back at Lincoln and saw he was right, all of the sunscreen had been rubbed in.
Between having his body rubbed and watching Lynn get the same treatment, Lincoln's cock was halfway hard. Luan could easily tell as the bikini bottom was really bulging outward. She also noticed that because the bikini bottom wasn't made to hold a bulge, the sides of his ballsack were showing.
Luan bit her lip and looked up at Lincoln, the two of them blushing as they looked each other in the eyes. As much as she hated to, she took her hands off of her brothers slender body.
By this time, Lynn had finished applying sunscreen so Luna and Sam were rubbing it on eachother.
"I might have to go an 'ave good wank after watchin' you ladies feel each other up." Chunk chuckled and took a sip of beer.
Upon seeing what Luna and Sam were doing, Lincoln could feel more blood being diverted to his penis, so he went and got in the pool so the cold water would make his boner would die down. Lynn followed, wanting to hide her half naked body behind the wall of the pool.
Feeling like being a bit of an ass and wanting to get back at Lynn for how crazy she used to go on "packing days", Luna suggested, "Let's go for a swim!"
Sam smiled and the while group got in the pool, except for Chunk who was content with sitting in a lawn chair and enjoying a beer.
As everyone piled into the pool, Lynn glared at Luna who gave her a wicked grin back. As she did this, Lynn tried to pee in the pool out of spite, but the beer hadn't made it that far through her body yet.
"How's that bikini feel, Lincoln?" Sam asked tauntingly.
"Fine." Lincoln rolled his eyes.
"I think it looks really good on you." Leni smiled, "It's a shame it doesn't completely cover your balls, thought."
Luan giggled as Lincoln blushed and covered his crotch with both hands.
"I think your siblings have been humiliated enough." Said Mazzy.
"All right," said Luna, "You two can swap back swimsuits."
"Thank fucking god." Lynn growled and climbed out of the pool. She then grabbed a towel from the stack of them that Lina left of the grass and wrapped it around herself.
"What if I don't want to?" Lincoln joked before immediately getting a death stare from Lynn. Knowing she wasn't kidding around, Lincoln got out of the pool as well.
As he bent over to grab a towel, he heard Leni say, "See, I told you he has a cute butt!"
Despite being surprised by hearing that, Lincoln grinned a little and smacked himself on the butt which got him a whistle from Mazzy. Lincoln then dried off and followed Lynn into the house. Once they went upstairs, Lynn headed for the bathroom with Lincoln following behind. He noticed she was somberly looking at herself in the mirror. He took off the top he was wearing and offered it to Lynn, saying, "Here's your top back."
"What's the point?" She asked, "It's not like I have anything to put in it."
"If you don't have anything to put in it," Lincoln asked, "why were you embarrassed about not having it."
"That's just it," she explained, "not only did I...not win the bet, but I don't have anything to show off."
Lincoln tilted his head, "You always say you don't need boobs."
"I don't." Lynn turned to face him, "But it just seems kinda unfair that the other girls have nice racks and I don't."
"Well...you've got nice nipples," Lincoln said as he looked at them; they were still hard from the cold pool water, "if that makes you feel any better."
"You perv," she responded with a smirk, "starin' at your sister's nipples." Before Lincoln could respond, she grabbed both of his nipples and gave them a hard pinch. "Ow!" He cried and did the same to her.
"You little shit!" Lynn cried. She then tried to push Lincoln to the floor, but he backed up through the doorway and into the hall as she continued to push him. He turned and put his back to the wall, hoping she would fall forward, but instead she ended up pinning him to the wall. They stared at each other for a moment before she suddenly shoved her face into his and kissed him.
As they continued to make out, Lincoln closed his eyes and wrapped his arms around his sister. Lynn then reached down and untied the bikini bottom he was wearing and pulled it off, leaving her brother stark naked with a growing erection.
Lincoln slid his tounge into his sister's mouth and wrapped his left leg around her. As she rubbed her tongue against his, she put her hand on the bottom of his ass cheek, then pulled his other leg up and wrapped it around her. He held on tight as she carried him down the hall and into his room, the two of them making out the whole way.
Once they were in his room, she dropped him on his bed. Lincoln got comfortable as Lynn climbed on his bed and onto him. Once Lynn was straddling him, she wasted no time slidding her brother's hard cock into her wet, virgin pussy. She had already broken her hymen years ago playing sports, so like her brother, the only feeling she felt was pleasure.
Lincoln and Stella Zhau had platonically lost their virginity to each other a couple of years prior, but Lincoln hadn't gotten laid since then, so once Lynn started grinding on her brother's cock, it felt like it was his first time again.
After a minute of grinding, Lynn leaned forward and put her hand on Lincoln's chest, giving her the leverage she needed start hopping on his cock. Lincoln moaned and grabbed his sister's firm, muscular ass.
Being athletic and full of lust, Lynn started riding her brother hard and fast. Lincoln might have worried about his bed breaking if he wasn't so preoccupied by the vigorous ecstacy he was getting from being inside his sister's pussy. He gripped her ass hard and kept moaning and gasping repeatedly while Lynn was full on yelling from the pleasure she was getting from her brother's nice, hard dick.
As Lincoln felt himself getting close to climax, he felt Lynn's genitals clamp down on his as she let out a very loud growl. She gripped his chest so tightly that she dug her fingernails into his skin, not enough to draw blood, but still hard enough to cause pain.
After Lynn's orgasm ended, she released her grip on her brother's chest and opened her eyes to look at him. Breathing heavily, she smiled and said, "You're a sick man, Lincoln Loud; making your sister cum on your big, sexy dick."
He grinned and said, "I'm not done yet."
"You're not?"
"Digging your nails into my chest kept me from coming."
"Aw, did I hurt Link winky?" Lynn teased and kissed the marks on Lincoln's chest. She then kissed him on the mouth and said, "Time for you to be on top, your scrawny ass needs a work out."
Lincoln rolled his eyes as Lynn got on her back. Then, he laid on top of her and slipped his penis inside. He started thrusting slowly but Lynn told him, "Harder and faster, Stinkon!"
"Are you seriously calling me that while we're having sex?" He asked as he picked up the pace.
"I'll call you whatever I want until you make me cum again, Stinkon." She replied as she wrapped her arms and legs around her brother, "Now fuck me like your life depends on it!"
Lincoln complied and started thrusting into his sister as fast and hard as she had ridden him moments ago. Despite there not being the sound of clapping flesh like before, there was still plenty of noise coming from his mattress and especially his sister.

Luan quietly closed the door to Lincoln's room and went into hers, making sure to close and lock the door behind her. Forgetting why she had gone inside the house in the first place, she sat on her bed and put her ear against the wall. It wasn't as hot as watching her brother's ass move in and out as he fucked their sister, but there was much less chance of her getting caught by just listening to the incest.
As she listened to her siblings yell and moan, Luan closed her eyes and replayed the image of her brother and sister having sex, then slid her fingers into her pussy and started fingering herself. She knew that voyeurism was wrong, but it was no worse than what her siblings were doing with eachother.
As she pleasured herself, Luan writhed and squirmed, trying her best not to moan and alert the others. She did let out a giggle when she heard Lynn say, "Oh my fucking god! Why haven't we done this sooner?!"
Finally, Lincoln let out a cry as he filled his sister's pussy with his cum. Soon after Lynn yelled in ecstasy as her brother made her orgasm a second time. Soon after that, Luan made herself orgasm, biting the knuckle of her free hand so as not to yell.
"Man, Stinkon, I mean Lincoln, that was awesome." Lynn said as she ran her hands up and down the young man's back.
"Yeah." He smiled before kissing her on the lips.
Indeed Luan thought to herself. She then got up, peeked out her bedroom door to make sure the coast was clear, and quietly rushed downstairs.
"What took you so long?" Luna asked Luan when she came back outside.
"Sorry," Luan replied, "I, uh, had to pee."
"So," asked Leni, "Why was Lynn yelling?"
"Well, her and Lincoln were...playing Guitar Hero," Luan replied, "she was loosing.
"Oh, ok." replied Leni.
A couple of moments later, Lynn came back outside in her bikini holding a bottle of water. Luan avoided eye contact and ate some chips from the snack table.
"So, how does it feel knowing your brother's dick was inside that?" Sam asked, pointing at Lynn's bikini bottom.
Lynn simply glared at Sam, where as Luan laughed, causing her to choke on her chips.
Luna chuckled at her sister's reaction, where as Leni showed concern, "Are you okay, Luan?" she asked. Luan grabbed the beer Lynn hadn't finished to wash down the chips. Once the chips were down, she grimaced at the taste it left in her mouth.
"You alright, luv?" Chunk asked. Luan nodded.
"It wasn't THAT funny." Lynn grumbled.
"Sorry." Luan croaked and took one more swig of beer before setting the can on the table.
"You should have told us you and Linc were playing Guitar Hero again," Luna said to Lynn, "were could have made another bet."
"What?" Lynn asked.
"We heard you yelling," said Leni, "so Luan went inside to see what was wrong. She said you were...you know, not winning."
Lynn gave a confused look to Luan, who's face was feeling a bit red. "I'm sorry," said Luan, "I know you don't like it when people beat you at stuff, but I figured it would be better if I told them you and Lincoln were playing a video game."
"Oh." Lynn said with a bit of hesitation, "It's ok, I guess."
Luna was surprised at how well Lynn took this, but shrugged it off and didn't bother saying anything.
As Lynn took a drink of water, Lincoln strolled out in his trunks.
"So what song you beat Lynn on?" Luna asked him.
Lincoln paused before speaking, "The same one you did, Pistol Grip Pump."
Lynn yanked the bottle from her mouth, causing a bit on water to fall on the ground. "Uh, she means means the second time," Lynn explained, "they heard me yelling a minute ago because you beat me again."
"Oh." Lincoln replied. Having caught on, he named the first RATM that popped into head, "Bulls On Parade."
"Really?" Sam asked, "That song's pretty easy."
Despite this being a lie, Lynn's pride was damaged enough for her face to turn a little red before she glared at her brother.
Realizing his mistake, Lincoln retorted, "Well, the solo is a bit tricky, and it's not like I won by much."
"Yeah," Luna said to Lynn, wanting to soothe her ego, "you scored pretty well with Linc earlier."
Luan snorted and started giggling, which got her a glare from Lynn.
"Luan," Luna chuckled, "you've got a dirty mind."
"I'm sorry." Luan replied before heading inside get something to drink more enjoyable than beer. She went to fridge and grabbed a bottle of apple juice. When she turned around, she saw Lynn with her arms crossed. Luan said, "Hey." Before getting a glass from the cupboard.
"Thanks for covering back there." Lynn said.
"No problem." Luan replied as she poured herself some juice.
"Look," Lynn continued sheepishly, "I didn't mean for it to happen, it was just a one-time thing..." Wanting to lessen her sister's embarrassment, Luan said, "There's nothing wrong with masturbating."
"Masturbating?"
"That's what you were doing, right?" Luan replied and took a sip of juice.
Thinking that Luan didn't know that Lincoln was involved in her sexual activity, Lynn felt a wave of relief wash over her.
"It's ok, we all do it." Luan continued.
"Well, I'll try to not be so noisy from now on." Lynn said, unfolding her arms.
"Especially not when the younger kids are home." Luan added.
"Yeah," Lynn smirked, "Lisa will probably want to do a sudy on it."
"Yeah." Luan chuckled and took another sip of juice.