It had been a month since Rebecca had been introduced to Abby as her new 'sister' and Abby had never been happier. Rebecca was a beautiful girl and Abby couldn't get enough of her warm caresses, soft lips, and juicy pussy. Abby was grateful for every opportunity Master gave her to play with her sister. The sessions were even more intense when the two girls were permitted to worship their Master together. The girls would spend hours kissing, licking, and sucking all over Master's body and He would praise them for catering to His noble lusts so thoroughly. The three of them were a perfect match for each other. Abby felt completely fulfilled.
Master was feeling confident about His girls as well. They seemed to take to each other very quickly after Sir Benjamin dropped Rebecca off to them. He certainly did a fantastic job of training Rebecca for Him. Master had considered sending Abby to Benjamin also but decided to handle her training personally. After all, He had discovered her, watched her grow and strive to become the slave He wanted her to be. He was the one who liberated her from her inhibitions, at least where He and Rebecca were concerned. It was time for Him to propose an idea to His delightful slave girls and see how they, Abby specifically, reacted to it.
He leaned back in His chair and gazed at His girls in the kitchen. They were cleaning up the mess from this evening's dinner and having a good time doing it. He loved to watch them when they didn't realize He was doing so. Master observed them often after Rebecca joined the household, looking for signs of jealousy or animosity. None appeared.
His cock grew as He stared at them, working so diligently to keep His home in order. They were so cute in their matching outfits. Master didn't require them to wear uniforms like a maid or nurse, although the thought had crossed His mind. Instead He preferred lingerie. He bought them the exact same sets, just in different colors, their favorite colors. He never ordered them to wear the same sets on the same days, but they seemed to do it anyway. Master found it rather endearing. Today they had chosen a two-piece babydoll set. The bra style top was just sheer enough to show off their sweet nipples, the body was a gorgeous flyaway mesh material with a high side slit on either side and came with a g-string. If they were going to wear panties, even if it was only on occasion, He preferred them to be as skimpy as possible, showing off their asses. Abby's set was in royal purple and Rebecca's in indigo blue. They looked devastating.
Master could see that they were almost done cleaning up. As was required of them, He knew they would report to Him immediately upon finishing their task, so there was no need to beckon them. Only a couple of minutes passed before the girls were standing before Him. They each placed their right foot behind them, curtsied, bowed their heads and fell to their knees. They kept their eyes lowered and waited for Him to acknowledge them.
"I am so lucky to have such wonderful girls in My service." Master praised. "Please, raise your eyes My slaves. I have something important to discuss with you."
"Thank You Master." The girls chimed in unison.
"Master Matthew has invited us to a play party in two weeks. Now that Rebecca is properly settled here and seeing that the two of you get along so well, I have accepted His invitation"
Master paused for a moment, waiting to judge their reactions. Rebecca's eyes lit up immediately. Abby looked uncertain. It was the first time Master hadn't seen a duplicate reaction between the two of them in three weeks. He wasn't sure what to make of it just yet.
"He will be hiring a lifestyle-friendly caterer and wait staff for the evening, so You will not be service slaves for the evening. The only things you two will be required to do are look ravishing and entertain His guests, of course."
Rebecca was positively vibrating. Master could see her trying to contain her excitement. Abby still looked unsure, confused even. He could tell she had questions, possibly even reservations. Normally Abby wouldn't have expressed these kinds of emotions. Due to earlier tests He had given her, she had learned to trust in Him and never question His intent. Master needed to understand her unusual reaction.
"Rebecca, I can see you are already looking forward to the party. That pleases me. Abby, my dear girl, you look like have a question or two regarding the event we will be attending in two weeks. You have my permission to speak freely."
"Thank You Master. Please, what do You mean by 'entertain His guests' Master?" Abby looked genuinely concerned about the answer to her question.
Master smiled at His sweet, devoted slave. To Rebecca He said, "You understand what I mean, explain it to your sister."
Rebecca placed her left hand on Abby's right shoulder. Abby turned to look at her sister, worry present all over her face. She knew deep down that she shouldn't be apprehensive about anything Master tells her but she had a feeling she knew what her Master meant and it honestly scared her.
"Master Matthew will be inviting fellow Masters and Their slaves over. The Masters will be permitted to use us if They wish or watch us with Their slaves. There will most certainly be limitations on what Master will allow the others to do to us, for our safety. However, anything that is done to us can be watched by the other guests."
Usually feeling Rebecca's touch would inflame Abby's lusts but now she could feel the color draining from her face. Being used while others could witness it? How humiliating. Abby had certainly been used by strangers, and relative strangers, before. She had barely known Benjamin or Rebecca before she had been used with and by them. Xavier was a complete stranger when he had raped her. Still, somehow the idea of many people witnessing her sexual acts with another filled her with dread. Of course having Master and her sister noticing her reluctance filled her with shame.
