A, B, and C
Copyright© 2025 by A.B,and C
Chapter 1: Comprehension
Biography Sex Story: Chapter 1: Comprehension - A brother, a sister, and her best friend struggle to enjoy a sexual triangle without "committing incest". The parts of this story acceptable to this site and the locale you are reaching it from are true (except for our names). Those parts of the story that are not are strictly fiction. But, when a character says something, that's just their opinion, and must not be relied upon.
Caution: This Biography Sex Story contains strong sexual content, including mt/ft Consensual Lesbian Heterosexual True Story Incest Brother Sister Light Bond Group Sex Polygamy/Polyamory Anal Sex Oral Sex
Without knocking, my sister, Amy, walked into my bedroom. I was sitting at my desk by the window, doing homework. Why was she interrupting me again, I thought as I turned to look back at the door behind me.
But, I found myself unable to speak. Because Amy was completely naked. And her best friend, Bee, was equally naked. Bee also had a cloth gag in her mouth. And her wrists were tied together by the terry cloth belt of a bathrobe. Amy led her into my room with the belt as if it were a leash.
“Why are you staring at us?” my sister demanded.
Flabbergasted, I fumbled for words.
“Are you just going to keep staring at us, you pervert?” she said. “Why are you spying on your naked sister?”
“Spying? You’re in my goddamn room!”
“I don’t see how that matters,” she said. “A brother really should not be spying on his sister when she’s wearing no clothing, no matter where she is.”
“I’m not spying,” I said, grabbing my book. “I’m doing fucking geometry!”
“Oh my God!” she said. “You’re such a loser! You would choose geometry homework over fucking a hot babe?”
“You’re my sister. No matter how hot you think you are.”
“Not me, dipshit, Bee.”
“Yeah, she seems to not be saying a whole lot right now.”
“That’s probably because I stuffed a pair of your underwear in her mouth.”
“You put my underwear ... in Bee’s mouth?”
“Don’t worry, it was a clean pair.”
“Why don’t you two just play your little game somewhere else? I said.
“Game?”
“Yeah, you’ve been teasing me like crazy lately.”
“So,” she said with an evil grin, “what I’ve been doing is getting you hard?”
“Damn it, Amy, you know what effect you’re having.”
“That’s just wrong. A brother really shouldn’t be getting hard at the thought of fucking his sister.”
“You just called yourself a ‘hot babe’.”
“No, keep up here. I just called Bee a ‘hot babe’. I’m your sister you shouldn’t even be looking at me.”
“Oy gevalt!”
“You can’t say that. It’s cultural appropriation.”
“Oh my God! You’re nuts.”
“Most guys like crazy girls.”
“Crazy fun, yeah,” I said, “but you’re actually ‘ha ha, ho ho, funny farm’ nuts.”
“Well that’s okay. ‘Cause you can’t have me.”
“Who said I wanted to,” I said, wondering what I wanted. “You just enjoy teasing me.”
“You can have Bee though.”
“I don’t think she’s yours to give.”
“Well let’s ask her,” Amy said, turning to her friend. “Bee if you don’t want Coy to fuck you say no right now.”
“See, she didn’t say anything,” she said returning to me.
“That’s because her mouth is full.”
“Yes of your dirty underwear, you pervert.”
“You said they were clean.”
“Hey, they are your underwear not mine.”
Then I watched as my sister pushed Bee onto my bed. She dropped to her knees on my rug and slowly, sensually, she went down on her best friend.
At first I was amazed. Then I was aroused. Then it dawned on me that this was just a new and even more cruel way to tease me. Amy was enjoying herself, and the way Bee was squirming she clearly enjoyed it. My cock was straining against a duplicate of the underwear in Bee’s mouth.
Then it dawned on me that the casual familiarity between them, their interaction ... it screamed to me that this wasn’t the first time Amy munched on Bee’s twat.
“Makes you kind of jealous doesn’t it? Amy said, after Bee had quite obviously come.
“You know damn well it does.”
“You didn’t have to stand there and watch.”
“You’re on my fucking bed.”
“You aren’t getting it,” Amy said with that evil grin. “Well, I shouldn’t be surprised. I mean at your age, your bed really should have some pussy drippings soaking into the mattress.”
“You just got to keep up with the teasing aren’t you?”
“I’m not teasing. I’m stating facts. You’re. Not necessarily of me, but just that lots of guys think it’s easier to be a girl. Because you think that we don’t get rejected. But then girls, we think it’s easier to be a guy. Because they get to choose. I can’t say ‘yes’ to somebody who never asks me.
“So, you’re teasing me to get me to ask you...”
“Oh God! No, you’re such a pervert! You’re my brother if you were to fuck me ... that would be incest ... and it would be wrong! Don’t you have any brains?”
“So why are you teasing me?”
“I’m not teasing you. You’re just not getting it.”
“What am I not getting?”
“Okay doofus. Teasing is when you put something out in front of somebody that they can’t have. Maybe even making them want it more.”
“Isn’t that exactly what you’re doing?”
“No. You are the one saying that you want to fuck me. And you are saying that you don’t care that society says you can’t.”
“God damn it, Amy. What I’m saying that you’re crazy- and yes quite cute in a crazy kind of way ... and yeah, you are fit and you are trim ... and tons of guys would want to fuck you. But you are nuts. Look in the fucking mirror you’re standing naked in your brother’s bedroom with your face covered in Bee’s pussy juice.”
“Would you like to taste?”
“What?”
“I’m asking you if you would like a taste of Bee’s pussy juice.”
“Well,” I stammered, “yeah, of course I would.”
“Humm,” Amy said,” hat presents a dilemma.”
“See you are teasing me.”
“No, you can actually taste Bee’s pussy juice. But the problem is that she can’t really ask you to taste it right from the source.”
“She can’t?”
“No, she’s gagged.”
“But a minute ago...”
“I know it’s hard,” she said dropping her gaze to my crotch. “But try to keep up. You can’t focus on the future if you’re living in the past.”
“Huh?”
“You’ll have to taste it off of me. But if you were to like lick my face...”
“Who said I was licking you?”
“I knew it!”
“No...” I said.
“I mean I know you want to lick me. Just like I did Bee. Because you’re such a pervert. But that would be you getting me off not you tasting Bee. Fun, but not something we are allowed to do.”
“I didn’t... ‘fun’...”
“Licking my pussy, as much as you really want to, is out. And, well, if you were to lick my face, that would still be awfully close to incest.”
“But,” Amy said after a pause, “you know what? I have an idea.”
My sister took her tongue and licked her lips before taking her finger and wiping the combination of her saliva and Bee’s pussy juice off them and extending that finger to me.
“What’s the matter?” Amy said. “I mean even if you could lick Bee’s aching cunt right now, there will be plenty of my spit down there.”
She had a point.
“Suck my finger, you perv.”
I did, and it tasted really nice.
“Oh,” she said, “you liked that, didn’t you?”
“Of course.”
“Maybe you’ll get more ... or more ... or more of more.”
“Well, what are you proposing?” I said.
“Maybe if you fucked Bee right now- and weren’t a huge disappointment- it could get to be a regular thing. Other stuff too.”
“Is this a joke? Are you teasing me again?”
“No, like I said, teasing is when you hold out something the other person can’t have. You can have Bee’s ass right now.”
“Her ass?” I said.
“It’s got to be her ass because neither one of us are on the pill, and I don’t suppose that you have two condoms there in your desk drawer?”
“‘Two’,” I said, quoting my sister.
“You are such a fucking pervert. You can’t fuck me, but you could fuck her twice.”
“Oh,” I said. Wondering if the disappointment in my voice was real or...
“Don’t you want to fuck Bee?”
“Of course I do.”
“Well that’s good. Because she’d be really disappointed if she didn’t think that you thought that she was good enough for you.”
“I never said that.”
“I mean if you were to say that my best friend wasn’t good enough for you I could never fuck you.”
“What?”
“You heard me.”
“You just said you could never fuck me.”
“God! That’s what I keep telling you. You’re not only a pervert you have a one track mind. Hi, I’m Coy, and all I can think about doing is fucking my little sister Amy. I’m Coy, and all I can think about doing is fucking my sister Amy.” she mocked.
“That isn’t all I can think about...” I said. Instantly realizing my gaffe
Oh, so you think about things other than just fucking me!”
“That isn’t exactly what I meant.”
“That’s a curious way to put it. It wasn’t exactly what you meant. But it wasn’t exactly not what you meant either. It wasn’t even substantively not what you meant.”