I will have harmony in the harem. The girls know this from the day they arrive. I know better than to require perfect pitch. There will always be competition, petty jealousy and idle bitchiness when sex slaves are held in close quarters. Where punishments are plentiful and favours are few, some competition is inevitable. But every girl within these stone walls must cooperate smoothly, whatever her personal relationships, for the pleasure of her master. For the use of their owners, they must function interchangeably, finely tuned instruments of satisfaction without a discordant note ever reaching the ears of those who own them.

It's a delicate balance. We do want the little darlings giving us their best in the hope of winning our approval, but obvious competition leads to petty acts of sabotage worthy of spoiled school brats, and I'm keen to spot it. My job as Director of Discipline is to spot potential disobedience and act ruthlessly to discourage it. I take pride in my work, knowing that any master could take any of the slaves I supervise in whatever number with absolute confidence in their cooperating to satisfy him.

My eye is on Astrid and Mia from the day they arrive. I can see they're attracted to each other, and to the same kinds of men. At first, it's cute, the way they try to outdo each other in their eagerness to serve. But mean, little digs begin to sneak into their conversation. All the girls have favourites, and it’s bad form to deliberately play up to someone another slave begs to worship. Eventually, there are harsh words and then sullen silence, which is what I find in the dungeon where l’ve had them brought to me. Wisely, they greet me with pleasant expressions, but neither cares to deny her spiteful conduct toward the other in recent days.

What to do? They are sister slaves and they will learn to give each other proper affection before either is allowed the privilege of attending to me. They will please and be pleased, unless they prefer to share in each others punishment instead. That suggestion gets a quick vote for reconciliation.

Astrid is first on the X-frame, standing spread-open in her leather working harness and strapped rigidly into place. Her pussy is offered to Mia‘ s oral affections, which strikes me immediately as a bit lacklustre, which is especially telling given Astrid’s delectable girly bits.

I get down next to Mia for some close-order instruction, seizing her by the hair and around the neck, manoeuvring her sweating face deeper into Astrid’s already dripping gash. These girls have long had all shyness and modesty trained out of them, so I assume the worst motives when either is less than enthusiastic. Clearly, Mia takes me seriously as she should, burrowing into Astrid’s pink slit hungrily, lips and tongue finding all the places that girls know so well. Mia’s posture is admirable and her efforts more committed as Astrid begins to moan and twist in the straps. I've yet to meet the slave without pride in what she can do with her mouth, and Mia is no exception, asking permission to work from underneath. Granted, of course. She slides between Astrid’s long legs, sucking and lapping from the clit all the way back to Astrid’s tender, exposed anus.

This is the humility I want to see. To encourage it, I turn Astrid on the frame and buckle her in again, feeling her sweating, trembling body's yearning for release. Not yet. First, I want to see Mia's clever tongue swirling in Astrid’s puckered hole.

There are whips nearby, and a quick reminder has Mia spreading Astrid’s cheeks and working her pink, pierced tongue into her former rival’s tailpipe. Astrid thrusts her ass out to meet Mia's delving, not out of spite, but out of the kind of pure lust she's been trained to set free when permitted. She writhes and gasps in her bonds, inspiring me to play with her clit, pinching and stroking the hard pulp, until the inevitable shaking begins. Cries echo from the dungeons stone walls, pleas for permission to come. I don't grant it quickly, wanting both girls to work for their respective rewards.

Gripping Astrid's cunt firmly, I feel it pulsate under my palm as her orgasmic howling fills the room. Good thing I’d given her leave to go there, else she’d have been in even more trouble, which I suspect might have been what Mia intended.

In all fairness, I believe Astrid to have done most of the provoking and I‘ ve already decided to make her demonstration of amity a bit more demanding, though we start in the same way. Still panting and sweating, legs a bit shaky, she steps down from the frame and helps me strap Mia there in her place.

I do appreciate Mia’s lush, meaty, meticulously shaved cooze, I tease Astrid with it as the latter kneels dutifully, agreeing with my vulgar praise of Mia’s intimate anatomy, however she might feel about the girl attached to it. In fact, she looks at all that pink membrane quite hungrily. Given leave to touch, she tugs Mia’s slippery lips apart to explore the bound girl's fuckhole with fingers and tongue. Astrid is the more experienced of the two and I've noticed her tendency to show off her abilities in such circumstances, Using her teeth with just the right pressure, she opens Mia wide, lapping and slurping as eagerly as if Mia were her favourite slave sister.

Perhaps after tonight, she will be, but I require more proof than Astrid doing what she does whenever a pretty slit is placed within munching distance. I bring out the dick gag. It’s a truly nasty thing, with an interior rubber cock that sticks down the wearer's throat almost as far as the exterior one plumbs the recipient's pussy. The harder Astrid fucks Mia with it, the more she'll choke and gag herself. But I know Mia is a girl who gets off on penetration and to get the desired response, Astrid will have to drill her hard and deep. I buckle it around Astrid's head good and tight, her nostrils flaring at the rude intrusion of the internal prod.

This is going to be good. A slave’s pride will punish her more effectively than anything a master might inflict. Sure enough, once excited, Mia proves predictably ruthless, grinding her weight down against Astrid's face, driving the twin dicks deeper into both of them. I hold the back of Astrid’s head to make sure she can't retreat, even if she were so inclined. it’s a needless precaution. Despite her retching and drooling, Astrid reaches up to grip Mia's ass cheeks, deliberately impaling them both rather than back away from the test put to her.

It's an inspiring spectacle. After a merciless face fucking, Mia suddenly stiffens, thrusts her pelvis all the way down onto Astrid’s packed mouth, and comes with an ecstatic scream accompanied by waves of rippling convulsions. She's forgotten to ask permission, but under the circumstances I do no worse than make her suck her own secretions off the soiled dildo while I grip the front of her throat. I push them together until their mouths meet and they're both fighting for air. I'm quite certain it's an intimate moment they’ll never forget.

Now it's time for them to demonstrate how smoothly they can work as a team, with their differences a thing of the past. If they want out of the dungeon, they‘ ll have to satisfy me first, and they get right to it. Passing my cock back and forth like a fat reefer, they take turns, one sucking while the other eagerly licks my ball sac. I don't miss it when their eyes meet with a conspiratorial twinkle. Sisterhood has clearly been restored. I'm particularly impressed with the way Mia swallows my whole shaft, showing off for her team mate. But the real dirty work is yet to come, when I stake Astrid on my lance, leaving Mia’s talented tongue to lend encouragement from below. Rimming me for all she's worth, her movements speed up as Astrid rides the rod to another shuddering climax.

I never cease to be impressed by the way her cunt muscles milk a cock. No wonder she's always in demand here. Thoroughly convinced of the sincerity of their reconciliation, I’m ready to grace their lovely faces with the proof of absolution for their sins. They kneel before, two pretty faces upturned, two sets of wide open eyes pleading to please. When I let go the pent up load of lava, they extend their tongues to touch tips, making sure to catch every spurt that doesn‘ t end up frosting their flushed cheeks.

My work is done. I tell them to get cleaned up and prepared for their next shift. They'll be working doubles the rest of the week. I hear the distinct sound of high fives as they make their way from the chamber. It's such a pleasure to make two estranged friends come together, especially when I get to come with them.