Step back and let her work.

You get off the bed, hands raised in submission. She scowls at you until you're nearly halfway across the room and goes back to tightening the ropes on Heather. The younger sister is eventually left with her head against the bed, her wrists shackled to the bedposts, her knees tied to her elbows, and her naked ass spread and sticking out above her. You can't imagine that can be comfortable, but Heather catches your eye and winks, her eyes smiling. Moving to a different angle, you can see Heather's pussy glistening in the morning sunlight.

Ashley stomps around the room briefly and goes into her closet, moving a pile of dirty laundry off a plastic storage box you've never noticed before. She brings the whole box over to the bed and starts rummaging around in it. A pair of large vibrators emerge. Ashley replaces the batteries on one, then attaches an external battery pack to the other. She turns on the smaller of the pair.

"Recognize that sound, Heather?" It buzzes loudly. You can see Ashley's hand shaking with its vibrations.

"Yes, Mistress. It's Enormo. Will you please fuck my pussy with it?" Heather sounds like the perfect submissive. Ashley turns 'Enormo' off and picks up the other, the one that required an outside power source. When she turns it on, you can swear your innards vibrate from the sound of it, despite being across the room.

"And this one?" Ashley's voice is slightly distorted as she tries to keep from shaking under the larger toy herself.

"That is.... I'm sorry, Mistress. I don't know what that one is." You move back to where you can see Heather's face. At this angle, Ashley can see you, too, so you don't try to tell her. The look of confusion on the younger sister's face tells you she truly doesn't know what's behind her.

"Then I guess your pussy has to tell you," Ashley says, spanking Heather's ass loudly. You don't need to move to know there's a large red handprint on Heather's backside now. Ashley turns the toy off and starts to push it into Heather's wetness. Heather cries out in surprise and pleasure as the large toy stretches her pussy wide. You're amazed how much of it fits inside her before Ashley again asks, "Which toy is this?"

"I... I don't know, Mistress. Please forgive me. I don't know this one." Ashley gives Heather another sharp spanking, sparking a yelp of pleasure-pain from the bound girl.

Ashley gives you a sexily malicious smile, then turns on the toy. Heather screams in surprise. Ashley then surprises her more by turning the toy's vibrations to their maximum setting.

"Oh, God..... M-M-M-Mistress, may I call this one Giganto?" Heather moans and tries to rock herself further onto it.

"You may, slut. You're going to come on it and christen it Giganto." You'd known Ashley capable of rough play and knew she loved to talk dirty during sex, but you've never seen this side of her before. "And since I know how much you love having giant things up your ass, you're going to have Giganto and Enormo both." The last comment gets a look at you from both girls. Both look like they want your cock.

Ashley lubes up Enormo and applies some to Heather's ass, then inserts the toy. It's every bit as deep as Giganto when she turns it on and sets it to match the larger vibrator. Heather moans and tries to move her butt around.

"Mistress.... May I.... Oooooh..... May I commmmmmmm-oooooooh........ May I come now?" Heather sounds needy. Ashley moves to the open space between Heather's arms and sits down in it, her legs resting on either side of Heather's knees.

"I come first, slut. Then you can come. Faster you eat me out and get me off, faster you get to get off yourself." Ashley grabs Heather's long red tresses and plants her face against her hairless snatch. Heather's tongue and lips go to work; you move closer to watch as Ashley's eyes close and her breathing becomes more rapid. Heather glances at you and winks again, then moans into Ashley's pussy.

Ashley's eyes snap open and she pulls Heather's hair back, forcing her sister to look up at her. "What did I say? You get me off first. Then you can get off."

"Yes, Mistress. I'm sorry, Mistress. But your toys just fill me up so well...." Heather goes back to work, darting her tongue in and out of Ashley, then sliding upward to tease and lick Ashley's clit. Ashley runs her hand up your leg, smiling at your hard penis staring back at her.

"Uuuuuhhhhhh, yeah........ Right there, like that, like that, likethatlikethat.......," Ashley moans. You reach down and gently fondle her breasts, pulling on her nipples as she starts to shudder in orgasm. She moans loudly, even as Heather continues to lick and nibble on her pussy. Ashley eventually pulls her sister away from her dripping slit. "Alright, slut.... You can come now."

Ashley gets off the bed, leaning heavily on you for a few moments as she recovers. Heather moans in the background as Ashley digs out a blindfold and wraps it around her sister's head. Ashley moves back to you, crushing your penis between your two bodies as she wraps her arms around you and plants a hot kiss on your lips.

"Let's leave her here with those and go fuck somewhere else." She smiles playfully and tickles your chest. You love this new, hornier side of your girlfriend.

"God, I love you. And I love you more and more as this weekend goes on," you tell her as you squeeze her ass. "Where to?"

Ashley thinks for a moment and makes a suggestion.