She's jealous, alright, and she takes it out on your ass.

Your stomach tightens with every step you take down into the basement. Emma can clearly sense your trepidation. Hell, she can practically taste it, but since Cindi put her in charge of your sordid study session, you just have take your licks...maybe literally. You aren't sure which scares you more, the spark of excitement in her eyes at the thought of having you are her mercy, or how throbbingly turned on you are at the thought of your seductive sister twisting you inside out.

"Tee Hee! Look how scared you are of lil' ol' me. Heh. I guess you aren't as stupid as you look then. You should be afraid after the way you tried to show me up in front of my Mistress." Emma leads you to the center of perverted playpen beneath Cindi's palatial estate. You are surrounded by infernal devices of unparalleled pleasure and unprecedented pain, and you aren't sure which worries you more.

"Relax, sissy. I won't hurt you TOO bad," Emma SPANKs your plump, pantied ass sending sweltering, stinging throbs up your spine and to your drooling clit. She rubs your reddened cheeks and whispers, "not with Mistress watching, anyway." Your arms are pulled behind your back and you feel a fluffy but firm bite into your wrists as Emma handcuffs you. "These are my favorite pair. Cute and soft like me, and once they've got you they won't let you go."

Emma drags you over to a leather bound chair with a huge, imposing dildo affixed to the floor. You notice the chair looks comfy with lots of legroom while the dildo is made of increasingly wider bulbs that just looking at makes you wince. Emma sits in the throne-like chair, and unsurprisingly, points out that your seat is the dildo, "Let's see who is better at taking it up the ass now, slut."

You struggle with the zipper on your pvc panties, which Emma takes clear delight in. You squirm and strain and you feel like your shoulders will pop out of their sockets any second, but you somehow manage to work past the pain. As you feel an odd sense of accomplishment for exposing yourself with your arms tied behind your back, it dawns on you that you started down this journey to avoid pain and embarrassment, and now you are getting much more of both, only in a way that turns you on so much that you just beg for more. This is what goes through your head when you start to slowly slide down the tapered **** device stretching your ass wider than it's ever been spread.

PLOP

The first knob is the easiest, a pleasant feeling that tickles your naughty nerve endings and has you hungry for more.

PLOP

The second is a little wider, but the segments seem well lubed and it slides inside you with no resistance, sending throbs of hungry heat radiating up your groin.

PLOP

Third time's the charm as the thiccer knot requires a little oomph on your part which causes the head to push up against your sticky spot and sends a single spurt of pent up cum shooting inside your panties. You moan wantonly, not caring who is watching as your face flushes fetchingly and your tongue lolls lewdly.

PLOP

"If you're going to let your tongue hang out like a slut puppy, then you might as well put it to good use, sis'sy!" Emma yanks you painfully by the hair to bury your face in her wet folds. The stabbing in your scalp echoes the searing stretch of the next segment. Your mind reels as it tries to process the perversion of making out with your twin's twat while the pain and pleasure in your overstuffed ass slow dances like prom dates. Your prostate is getting pressed hard by the second bulb and your clit is leaking like a broken faucet and your mental map is rewiring itself, rewriting the rules to correlate cruelty and cumming, agony and arousal, deviancy and desire.

PLOP

"That's AH it! The real trick to EEE eating PANT PANT pussy is to know WHIMPER when to make MOAN love to it...and when to tongue NNF fuck OOH it into AAAAH submission!" Emma offers pointers that go over your head as you dive deeper into her dampness. Some part of you must be taking it in however, as you spear your tongue deep inside her darting inside and out and using her wet whimpers to distract you from the exquisite agony and anguishing ecstasy of your overstretched ass.

PLOP

You feel cold concrete crush against your cheeks and you realize you have taken the foot worth of fuck balls up your ass and you unleash a flood of sticky spurts that slosh sloppily in your panties. You don't get long to enjoy this euphoric explosion before your sister yanks you off, yelling, "Don't ever stop slurping my slit until I tell you too! I bet if I was Little Miss Cindi-rella the Glass Dildo Princess, you wouldn't have to be reminded to kiss my cunt!"

PLOP PLOP PLOP

You begin bouncing brainlessly on your butt balls, sliding up to lap up Emma's juices and slamming down to fuck yourself senseless. The sight sends your slutty sister into spasms, spraying you with her gushes of glee as you struggle to drink it all down. You worry what the coroner's report will read if you drown in your sister's cumming cunt, but you also suspect you might have died and gone to Heaven. Emma is a bratty bitch, no doubt, and she plays rough, but you can't say you don't love her games.

Just when you are ready to go towards the light, Emma yanks you off your dildo PLOPPLOPPLOPPLOPPLOPPLOP and gives you a single second to gasp for air before plunging her tongue down your throat and lapping up her juices off your tongue. You feel a warped sense of freaky familial connection to her as she cleans your face with her tongue and shares her sweet stickiness with you. You lose track of time, lost in lust and the twisted tango of tongues as your orgasms wash over you in warm waves. For the moment, you forget Emma the Brat and just enjoy the moment with whoever this warm, affectionate creature is.

"Enough kissy face, losers! I'm not kissing either of you nerds so you can practice that at home. Speaking of which, I'll see you two here tomorrow to continue your training. In the meantime neither of you are to cum. And you know I'll know if you do!" Cindi's cold voice comes over the speakers and heats you up. You break the kiss, noticing how Emma whimpers softly and scowls at how quickly you obey your new Mistress. She gives you sneaky sneers as you clean up and get changed, and you can tell she is still jealous of you and Cindi. You suspect she plans to sabotage you between now and next morning, but you plan to be on your guard for every waking minute between now and then.