"You're really sure about this, Flutters?"
>Pinkie practically stuffs her hoof into your mouth to silence you.
>"Uh uh uh. She asked for it, so she's getting it."
>You watch Fluttershy's silent shock as Pinkie pushes you down against the bed, her wet mouth sucking and kissing around your neck.
>"Mmh. I can see why Fluttershy likes you so much, Nonny."
>Fluttershy continues to watch, eyes intently focused on you as Pinkie starts kissing further down your torso.
>When she reaches your underwear she pauses for a second to inspect the growing bulge contained within.
>"Wow, Fluttershy! If I didn't know any better I'd think Nonny was MY special somepony."
>With a giggle she tugs down the underwear and allows your cock to spring up into her face.
>"..and to think, you get to play with this every single night!"
>"N-Not EVERY night..." Fluttershy lets her hair fall over one of her eyes.
>"Oh yeah? You ever do this to it?"
>Pinkie maintains eye contact with Fluttershy as her tongue slowly, precisely, trails up from the base of your cock to the very tip, running her saliva along the fleshy underside and giving you an indescribably potent tingling sensation. 
>This mare really knows how to work this thing.
>She continues to stare at Fluttershy as she takes the head of your cock into her wet, eager mouth, covering it in her spittle and spitting it out again with a moan.
>"Hehe, I think I can still taste your pussy on there, Flutterbutter."
>The pegasus expels an eep and hides away more.
>"I wanna make sure this thing's nice and ready to go inside."
>She takes the entire thing into her mouth, a hot sheath, and pumps it down the back of her throat; you feel her tongue loosen and contract as your cock slides effortlessly over it.
>Fluttershy seems distressed but just continues to watch without making a single comment.
>"There. Nice and wet."
>Pinkie slides herself up over you, raised up so her dripping, swollen pussy lips sit just a few inches above the tip of your cock.
>"I hope you're watching, Fluttershy. You should take some notes."
>You watch as your dick sinks into her marepussy like it's warm, half-melted butter.
>Smooth, wet, with just the right amount of friction either side.
>You shudder, unable to help yourself, and hear Fluttershy let out another timid sound.
>Pinkie eases up and down, giving your cock a sheen of juices each time it reappears. She's taking control here and she wants you to know it.
>Fluttershy's blushing as deep red as she can, following the action up and down and seemingly both entranced and worried.
>"So, Nonny, how does my Pinkie pot compare to Fluttershy's cockatrice snare?" She giggles, panting as her hips come down a little harder against yours, meeting in the middle with a wet impact.
>She gives you kisses along your bare chest as she rides you, little sexually-driven moans leaking out of her in sensual drips.
>You don't even have to do any work, just lie back as Pinkie stuffs your member as far into her as it'll go.
>You can't stop looking towards Fluttershy, though. It must be as weird for her to see you fucked by Pinkie as it is for you to know she's watching the entire thing.
>"You gonna cum for me, Anon, or.. hnn.. are you gonna be thinking of your precious Fluttershy?"
"I-"
>"C'mon, fill me up. I know you want to. What? You need permission from your marefriend or something?"
>She giggles again, even if it sounds bubbly and light it's really malicious.
>"Well, Fluttershy? Do you give him permission to cum inside me?"
>She shakes a little. "I... um... maybe not... inside.."
>"Pssh. You're no fun. You WILL let him cum though, right? Wouldn't wanna blueball your boyfriend, would you?"
>"Um... yes."
>It's not exactly the most emphatic answer but it'll do; Pinkie lifts herself away and lets your cock free.
>"Well? You have permission. What are you waiting for?"
>To give you encouragement she bends down and applies gentle, ticklish licks along the rim of your head.
>"You arc your back and explode; sending several ropes of cum splattering over the mare's face, mane, and your chest and stomach.
>The orgasm is so intense you're shivering. Pinkie really knows her way around a penis.
>"Wooow! Look at all that icing!"
>You feel Pinkie's tongue lap up every last droplet she can, squishing it down against the roof of her mouth with a squelch and swallowing it audibly.
>"Hey, Fluttershy, get over here!"
>The pegasus hesitates for a moment but gets a little closer to Pinkie.
>The party pony gives her one last little spark of jealousy by breathing her cum breath right against her muzzle, telling her she's only worth a smell of what she missed out on.
>"..aaand, there we go! Boy, you should really ask me to help you out with weird sex things more often, Fluttershy, that was fun!"
>As if nothing has happened, Pinkie jumps off from you and leaves humming a song to herself.
>You and Fluttershy share a look. Neither of you is sure what exactly to say