They grab you

Trish and Heather look at each other and start grinning at the same time. You are a little dazed by your orgasm, and they stand up and run over to you, their tits bouncing erotically. They each grab an arm and lead you to the bed, making you lie down on it. Trish runs to the door and closes it, throwing the lock before she returns to the bed.

Heather has your arms gently pinned over your head, and she says, "So, you were watching us! Well, I guess that means you want to join the fun." Before you can say anything, Trish sucks your cock into her mouth, forcing a loud moan from your throat. Your body responds to her blow job, and your manhood is soon hard as rock. As soon as your eyes close in pleasure, you hear a loud click and feel what feels like hard fur go around your wrists. You snap your eyes open and see that your hands are now cuffed to the bed frame by fur-covered hand cuffs.

"Hey, what are you doing?" you exclaim.

Without answering, Trish quickly grabs one of your legs and starts cuffing it to the bed post at the bottom of the bed. You struggle quite a bit, but Trish and Heather combined get your other leg cuffed. You are now spread-eagled on your sister's bed.

Heather finally says, "So, you thought you'd watch us, eh? Well, since you had so much fun, now you get to be our toy for awhile." When you get a worried look on your face, she continues, "Don't worry. You'll enjoy it."

You watch intently as Trish crawls back between your legs. You see her mouth descend over your cock, while she looks you straight in the eye. She has a sexy, dreamy look on her face as she licks and sucks on you at the same time. Your body can't help but respond; soon you are back in the same ecstatic state she had you in before the handcuffs. She releases you and climbs up on top of you, straddling your hips and positioning her pussy lips around your meat. She starts rocking up and down, dragging your stiffness through her slit. Then she pauses slightly at the top and resets your cock at her cunt, and then pushes down, slowly enveloping you and sighing all the way down. Your nerve endings are singing. Suddenly, your sister's tit is pushed in your face; even if you wanted to, you can't stop, so you suck her nipple hard and nibble gently at it. It's Heather's turn to moan this time.

Trish says "Fuck me," at the same time that Heather says, "Ooo, suck it good!" You start pumping your hips up into Trish's body as she descends and flicking your tongue rapidly on Heather's nipple. They both gasp at the extra stimulation. You are in heaven: you've always found your sister to be sexy and now you are sucking her tit, and Trish has been a stroke fantasy of yours since she and Heather became friends and you now have your cock buried in her pussy. Who cares that they have you tied up?