Keep using Rosa

"Now that's what I like to hear!" You say, hopping up from the couch and grabbing Rosa by the hair. You roughly pulled her to her feet, bent her forward to a 90 degree angle directly in front of Lucia, and pulled both hands behind her back, holding them there by the wrists with one of your hands. Using your other hand, you lined up your still-hard dick against her asshole and began to push into her, using all of the spit she left on you as lubricant.

Rosa grunted as your meat stretched her tight rosebud. Once you were inside of her, you used your now-free hand to grab a fistful of her hair, pulling her head back so that she was looking directly into her sister's face. Your wife's hands snaked their way to her clit as she reveled in the show.

"Tell me how he feels," She commanded, staring into her sister's eyes.

"Master feels incredible, Mistress!" Rosa responded. "Master's cock is stretching me out so much!"

You thrusted hard into Rosa, quickly sinking your manhood all the way into your living sex toy.

"Ungh! It hurts, Mistress, but it feels so good!" Rosa continued.

You started pistoning in and out of her backside, slowly at first while you savored the feeling of her ass against your cock. You quickly picked up speed, eliciting a series of grunts from Rosa

*SLAP*

Lucia's palm made sharp contact with Rosa's cheek. "And how does it feel to be so helpless? To be so used?" She asked.

Rosa paused for a second before answering, blushing slightly less this time. "The loss of control is exciting, but the loss of everything else is...intoxicating. Having my dignity, my name, even my purpose stripped from me... it makes me want more of this!"

*SLAP*

"Your purpose is to make us cum. You live to serve!" Lucia corrected her.

"Yes, Mistress! Thank you for my purpose!" Rosa said.

"Say it. Repeat it." Lucia commanded. By this time, you were hammering Rosa's asshole at full speed.

"I live to serve! I live to serve! I live to serve!" Rosa shouted over the sound of your hips slamming against her meaty ass. "I live to serve! I live to serve! I live to serve!"

With one final thrust, you buried yourself to the hilt and flooded Rosa's rear end with your seed, letting out a satisfied groan as you emptied your balls for the second time that night. You held Rosa in her place as your orgasm subsided.

*SLAP*

Lucia's hand met Rosa's face one final time before she leaned in and gave her thoroughly used sister a tender kiss on her still stinging cheek. "And don't you forget that." She said sternly but softly.

Lucia then got up, walked over to you, and gently pushed you backwards before sinking to her knees and taking your dick into her mouth. She wrapped her tongue around the head and then slowly went deeper and deeper until she had your entire length in her mouth. Sucking gently as she went, she pulled her head back and then pushed her self back to the base of our cock again. Finally, she removed it entirely from her mouth with and kissed the tip, apparently satisfied with her cleaning efforts.