NOTE: this story presumes familiarity with the first two in the series. I suggest starting from the beginning. All events are based on true people and stories, and everyone was of legal age at the time.
*****
I stared at the scene unfolding in front of me. My girlfriend, Kim, lay on her back wearing only a little blue thong with a bow on the front. Her auburn hair was splayed on the couch behind her, and her legs were propped up at a 90 degree angle on top of mine, our knees practically touching.
Kim's 18 year old little sister, Katie, was laying on top of Kim, her mouth sucking on Kim's tasty brown nipples on top of her B-cups. Katie's straight brown hair spread over Kim's stomach, and her soft D-cup tits were wrapped around Kim's face. Katie's bare ass was popped up, facing mostly away from me, and just begging to be spanked. Katie's face moved down Kim's stomach, and she placed a little kiss on the bow at the top of the blue thong.
"Don't you want to taste your naughty sister?" I ask. "Stick your tongue in her pink wet pussy like she did to you. Tongue-fuck her."
"Mmm, I want to taste you so bad," Katie moaned into her sister's flesh. Katie sat up slightly, her own bare pussy hovering above and behind Kim's head, and grabbed the waistband of Kim's damp thong. Kim lifted her hips slightly, a move which always fills me with particular excitement. Katie slid the thong down her thighs, and managed to get one of Kim's legs completely out. Kim's thong remained around her left calf.
I reached down to open up Kim's legs, bringing her left leg out to open her thighs to my gaze. Her pussy was swollen and moist, her pink lips slightly parted with excitement. That little clit I love to nibble was practically throbbing.
Speaking of throbbing, I could feel my own cock start to pulse with my accelerating heartbeat as I watched the scene unfold before me.
Katie reached up to put her long straight hair in a ponytail holder she had around her wrist. Suddenly, she squealed with surprise and delight.
"Ooooh! Oh, that feels so good, Kim. Lick me right there!"
I could see Kim's head bobbing slightly, although most of her head was blocked by Katie's smooth thighs.
"Oh yeah, suck on my pussy, sis! Fuck, I'm getting so wet for you."
As Kim continued to work her tongue and mouth over her little 18 year old sister's pink slit, Katie started to ride her face a bit, cupping her full tits and moving her hips to her personal pleasure rhythm. Katie began to rub her thumbs over her light brown nipples, pleasuring herself in a bold display of pure sexuality as she face-fucked her sister.
"Mmmm, I've wanted to fuck you for so long, Kim. I've always known you were a subservient slut ready to do whatever I want to you. Eat my little teenage pussy, slut! Taste my cunt!"
I hear some muffled moans from Kim, and she pulls her head back from its feast for just long enough to say, "With pleasure!" Her hands go to Katie's ass cheeks, and I can see her pull them apart a little as she renews her assault on Katie's dripping snatch.
What a dirty mouth on this one. She's just as dirty as Kim, but not so passive. No wonder she gets in so much trouble at school. As Katie's breathing starts to increase in pace, she turns her gaze to my cock, now almost full hard.
"Mmm, I want that cock again," she coos. Well, then, I think I see my opening to maximize my pleasure out of this. I have something she wants, and as she gets closer and closer to orgasm, she loses more and more of her ability to say no.
"What are you going to do to earn it?"
"Whatever you want me to do. Please?"
"Call me sir, for starters."
"Please, sir? Please, sir, may I have your cock?"
"Are you going to do what I say?"
"I'll do anythi-mmmph!" She lost control of herself, her head rocking back as she moaned harshly. "That's it, suck my clit, Kim! Suck it right there."
"Kim is showing you a good time, isn't she?"
