Forbidden...But It Feels So Good

[Editor's note: while this story is in the Incest category, it also contains fetish elements like scat and golden showers.]

*

I watch with fascination as my younger sister by a year, Gemma, undresses in front of me. We are at a spa, preparing for the sauna and massages. We have seen each other naked so many times, so she was completely comfortable. I wonder if she knows that I am turned on by her body, whether she would be as comfortable.

I've always been bisexual, but I discovered when I turned 18 a year ago that I enjoy girls more than guys. Guys are just primal. In for only the deed, and then they run away. But girls, they stay and enjoy every part of the experience. Most of the girls I meet enrich the whole experience with . . . fetishes, and such. I have to admit, I have a couple fetishes. Most would consider them gross.

The first is piss and shit. Something about being that dirty is just such a turn-on. And the other is . . . incest.

My sister is gorgeous. She has long black hair, straight and silky, that hangs down to the middle of her back. Her eyes are bright green, the color of freshly mown grass. She has perfect lips, exactly between full and thin, and naturally pink. I want so badly to crush my identical lips to hers. Her body is to die for, as well. She is tall and graceful, with a shocking bra size of 32D, natural.

Who wouldn't want her?

And who wouldn't want me? I'm similar to my sister, but taller, a teensy bit curvier, and my hair is dyed blue for the moment. I'm going through a punk faze. My eyes are gray, and I have a touch of freckles on my cheeks. My proudest feature, though, is my 34DDs. Also natural.

I undress slowly, still a little absorbed in Gemma's body. I notice her pussy is completely shaven, just like mine. My nipples go hard, just as the robe falls from my shoulders.

Gemma notices and laughs, her ample boobs bouncing slightly as she does. "Feeling a little cold, Ivy?"

I laugh nervously. I'm relieved. What would be her reaction if she knew it wasn't the cold air in the locker room, but her sexy body that got me hard? "Yeah, it's freezing in here!" I exclaim with conviction.

Gems grins. "Well, let's go to the sauna, then! Come on."

She leads the way to a room with SAUNA on the door. As she opens it, a rush of hot steam pours out. She smiles and steps in. I follow.

The room is pitch black, and very hot. I can tell there's no one else in here, just because of the fact that when we opened the door, no one sighed in relief at the momentary cool air.

My pussy starts to tingle. Alone, with my sister, in a dark and steamy room? Not to mention we're both completely naked.

I can't do anything, though. Gems would freak out. I'm close to my sister, and even though it may not be in the way that I so badly want, I need to keep that element. If I came on to her, our relationship would be ruined forever.

I blindly make my way to a wall and sit down on the bench. Sweat rolls down my back, my face, and legs.

It isn't just sweat on my legs, though. I can't stop thinking about Gemma's shapely long legs, perky and tanned tits, her plump, kissable lips. Her shaven pussy.

I need to masturbate. My cunt in going wild right now. If I don't touch it soon and provide some release, I think I might explode.

What if she hears me?

"Gemma?" I say tentatively, just to see where she is.

"What, Ivy?" She answers, her voice drowsy. Was she falling asleep?

"Just wondering where you were. What are you doing?"

"About to take a nap."

"Okay."

We lapse into silence. She's taking a nap, so I will take my chance.

As soon as my fingers touch my cunt, I feel a warmth building up there. I think about how sexy my sister's body is, imagine fucking her, and almost immediately my climax seizes me. My mouth opens in a little O and my whole body tenses. I throw my head back and barely resist the urge to scream. I've never had an orgasm that strong before, let alone by my own making.

I breathe deeply, and continue slowly stroking my pussy, shuddering at its sensitivity.

As I calm down, pressure builds on my bladder. I have to pee, which is always an occurrence after a really good orgasm. I don't know why, but it's true. I stand up to leave and go to the bathroom really quick, but as soon as I do my pussy lets a little bit out. I must really have to go! I won't be able to make it to the bathroom.

Panicking, I mutter, "Gemma? You awake?"

No answer. She must have fallen asleep.

Inspiration strikes me.

I know for a fact that she is a really deep sleeper, so if no one comes in, I'll be able to get away with this.

I'm going to piss on her. God, my pussy gets wet just thinking about it, and not with pee.

I walk over to where I heard her voice earlier, and feel around. My hand lands on a warm, sweaty . . . tit. My eyes roll back in my head. Slowly, trying not to wake my sister, I knead it and squeeze. It's so full and firm. I want to kiss it, lick it, so bad.

So I do. I suck on her nipple like no tomorrow. My sister doesn't even stir.

I would keep on, but I really have to pee. So I slowly, careful not to jostle Gems, position myself over her leg, straddling it. My pussy is inches above her tanned, sweaty skin. I close my eyes, relax, and feel warm piss run down my legs, spray onto my sister's. When she wakes up afterwards, it will just appear very, very sweaty. The smell is masked by the steam.

When trying to get off, my sensitive cunt presses against Gems' leg, and it feels amazing. Not even caring about whether she wakes up, I start to rub my clean shaven pussy against her leg, touching and playing with my nipple with one hand, and playing with hers in the other.

I cum within a matter of seconds again, and again, it is mind-blowing. Does it have something to do with my sister, or am I just really horny today?

*****

When we get home, my sister totally oblivious, I fix dinner. While we sit there, eating dinner, I down as much water as I can. I want to piss again. I don't care if it's on my sleeping sister, on my bed, in the shower, or in my panties, but I want to wet myself again.

At eleven, we both go to sleep. Well, my sister does. I stay up, still gulping down water, getting ready for my piss. I've decided, since she stayed asleep for so long today t the spa, I'm going to piss on my sister again.

I creep in Gems' bedroom at twelve thirty, and climb on her bed, over her sleeping body, and stand up, straddling her body. I'm already naked, so I spread my legs wide, relax, and watch as hot piss sprays from my piss hole and onto my sister and her bed. In the morning, I'll just say the dog peed on her bed or something. He does that a lot, anyway.

Suddenly, she jerks on her back and stares up at me with wide eyes.

I freeze. I can't stop pissing, so it's still raining down her, but I stammer, "Gemma—I . . . This isn't . . . I mean—"

"Shut up." She says, grabbing my legs, making me fall on top of her, sitting up and on her stomach. "I want to shit on me." She murmurs aggressively.

"What?"

"Take a shit! Right now, Ivy!" she pulls me down and kisses, fiercely, her tongue thrusting itself into my mouth. I'm shocked for a moment, but choose not to question it until later, and kiss her back. I explore her mouth with my tongue, with circling her nipple with my finger.

She moans and pushes my head towards her ample tit. "Suck it, and then take a shit."

I suck, just like I did in the sauna, and she moans louder and louder. Then I lean my chest down and rub my tits on hers. It feels so good, so stimulating. I feel my pussy getting wetter and wetter.

"Yes, Ivy," she groans, leaning her head back and clutching my shoulders, "Rub my tits. Rub them red, you dirty slut!"

I love dirty talk, so I go harder, faster. Amazingly, I feel an orgasm coming up, something I've never heard of before. An orgasm by tit rubbing? Well, apparently it's possible, cause when I cum, so does my sister. She screams loudly and kicks her legs around underneath me. I can't stop myself from humping her as my climax takes full control.

We calm down, and she says, "Now poop! Right now, Ivy!"

I sit up, obeying, and strain. I feel my anus dilating and a huge turd slides out, followed by another, and another. Gemma moans under me, and scoops the shit up in her hands, and rubs it all over herself and me.

I had no idea how dirty she was.

After I'm done, she grins, kisses me, and says, "How about we do this every night, Sis?"

All I can do is smile and nod.