"Ask her," Ali said.

Ali was my long-term girlfriend and also my business partner. The her was Sita, our secretary, a cheerful 19-year-old girl of Indian heritage with a ready smile and a polite, helpful nature.

Ali and I had been discussing having a threesome and who it might be good to invite. We had been together five years and made no pretence of ever doing anything as sensible as getting married. We were kindred spirits, and had reached a stage where our sex life needed a boost. We had discussed bringing another man into the equation, but I just couldn't imagine it working. I certainly wouldn't have wanted any of our friends to join us and wasn't going to have some cocky chancer thinking all his birthdays had come at once because I would let him shag my woman. And anyway, the thought of being with a naked man just turned me right off.

Ali hadn't pressed the issue, and I felt she could handle having another female in bed with us. She might even have been nursing a nice, civilised sapphic streak all these years, so I would be doing her a favour. This was unspoken, though. All I knew was that she had approved the general idea and asked me who I wanted to proposition. When I suggested Sita, she mulled it over very quickly and I could see she liked the idea. But Sita was so respectable, she said.

"You are respectable," I pointed out. "I am respectable. And if we're considering it, why shouldn't she?"

"Yes, ask her," she repeated. "Or do you want me to?"

"No," I said. "It might freak her out if she thought she was being asked to turn lesbian. Anyway, she trusts me. She thinks of both of us as kind of parent figures and she would be being asked by a man, which she's used to, and it might be more acceptable. And at the back of her mind, she will be thinking there might be a bit of you and her in it. too."

"Which there would be," Ali said. "You okay with that?"

"No one must feel left out, that's all," I said. "But as we've said, we're all nice people so I reckon we can pull it off."

One night after work, the three of us went for a drink and when Ali saw some people she knew, she went over to talk to them. As she went, she nudged me.

So, here it was: the moment of truth. I had it worked out.

"Saturday night," I said. "You doing anything?" She said she wasn't doing anything special.

"We'd like you to come round to my place," I said, leaving acres of explanation space uncovered.

"Okay," she said, and picked up her drink. "Why?" She looked a bit worried.

"Nothing to do with work," I said hastily. "We just..." I trailed off, finding my script hard to stick to. "We like you," I continued, and looked at the table.

"And?" she asked, half convinced that this was indeed a proposition but needing to have it spelled out. A nervous smile played around her lips.

"We think we could have a good time together," I said pathetically. "The three of us." I left a pause that spoke volumes before adding, "Like a threesome."

"A threesome threesome," she said, toying with the words, just as Ali returned.

"What are you two so quiet for?", Ali asked.

"Vic was just telling me about Saturday night," Sita said.

"God," said Ali. "Haven't you sorted that out yet?" She looked at me, exasperated.

"We want you to join us on Saturday night for some fun," Ali said simply.

"What kind of fun?" Sita said mischievously. She didn't sound shocked. Amused, if anything.

"Sex," Ali said. "There. What do you think?"

"Let me think about it," the younger woman said. "I ought to be going anyway."

The next day, Friday, I half expected her not to come in. Ali and I were sitting, having a coffee when she arrived.

"Okay," she said, looking at us each in turn. This wasn't okay. How are you?

"Really?" Ali and I said in chorus.

"Yes."

"Great," we chorused again, and we all went silent.

"Oh, fuck it," I said, standing up. "This shouldn't be difficult. Now, we've all got work to do."

We all tried to act normal, but our minds were all in each other's underwear. Sita was so sweet and apparently innocent. We would soon find out if that was true. I had to wrench my eyes from her bottom every time she walked away from me and from her breasts every time she came towards me, and I could see Ali doing that too. It was a long day.

Saturday night came, and Ali and I were at my house, telling each other to play it by ear. Or should we have a plan? You kiss her. No, I'll kiss her. Why don't we just start having sex, and she can join in? But what if she changed her mind and just left? What if it all goes wrong? We would be looking for a new secretary. What if it all goes so well that it changes us as a couple? So, we could never do anything without her.

No, we eventually decided. It will be fine. She will be more nervous than we are. She knows what's going to happen. She will go along with whatever occurs, and after the first physical contact we'll be flying.

The doorbell rang, and Sita was standing there clutching a bottle of prosecco, her standard pleasant smile slightly squeezed by self-consciousness.

We sat in the living room, Ali and I on armchairs and Sita alone on the settee. And it was as quiet as I had feared it would be.

Then Sita reached into her pocket and pulled out a little pile of square paper notes, which she offered to Ali. "Are we going to do something like this?" she asked. Ali looked at the top note and smiled, then the second one and nodded her head.

"Okay," Ali said, with a little glance at me that said this was a good idea. "Let's sit on the floor."

We got down in what would have been a circle with more people but in this case was a triangle. Ali shuffled the papers and offered them to me. I took the top one. "Read it out loud," Sita said quietly.

"You will lick the pussy or suck the cock of the person on your right," I intoned mechanically. Sita was on my right.

"I think we have to be naked for this to work," Ali pointed out. She turned the dimmer switch down on the wall and we all undressed quickly, then sat down again. "Go on," Ali said encouragingly. Sita sat there demurely, as demurely as a woman can with her legs crossed, breasts on display and crotch hidden only by her ankles. As I approached her, she straightened her legs, so her feet were flat on the carpet in front of her and her elbows were on her knees. My cock was belatedly hardening as I knelt down in front of her and pushed her gently so she lay back. With my hands on her knees, I got into position and in a trice we had engaged in the traditional muff-diving set-up. Her crotch was unshaven. I parted her lips with my thumbs and put my tongue into her hot, sweet delta. She tensed a little, then relaxed as I sucked her clitoris. As we got into a rhythm and began to forget where we were, Ali coughed.

"There should be a time limit," she said. "Five minutes. Don't overrun." She was trying to be flippant, but it was apparent we were all going to fall at the first hurdle. No one must feel left out. As I reluctantly relinquished my position, with Sita glassy-eyed and trembling, Ali picked up the next paper and read, "You will masturbate the person on your left."

I left my post at Sita's crotch and allowed Ali to sit there, kissing the younger woman's knees as she located the clitoris and started to rub her expertly. Sita raised her head for a kiss and suddenly another obstacle to the evening's fun was gone. Sita and Ali were happily entwined, and Ali was working her magic with her fingers.

Should I raise the five-minute objection? If I didn't, Sita was going to cum. If I did, I would be spoiling the moment. But Sita could cum again - and I wanted her to. I wanted all the inhibitions to dissipate and sex to become our world for the night, with all of us open to anything, liberated from the normal reticence and with nothing off the table.

Soon, Sita spoke up, good girl that she was, not wanting to break any rules and abuse our hospitality.

"I'm going to cum," she said guiltily, before falling apart in a volcano of sexual excitement. They both looked at me.

She subsided in a deluge of feel-good brain chemicals and a deep exhalation, falling back to the floor. We all took a moment to regroup. Ali looked at me for reassurance and I smiled and nodded.

"Do we need to carry on with the cards?" I said hopefully. "Or shall we go to bed now?"

"Bed," said Ali.

"Okay," said Sita, and we trooped into the next room, where Ali had changed the bedding and turned it down invitingly. Black satin sheets, a bit corny perhaps, but they did make it feel extra naughty. We all sat down, wondering what was coming next, and again the girls looked at me.

"Sita's turn to do something," I offered. "How about sucking my cock?" As I had not been serviced so far, this seemed a fair, not to say logical, step. I lay on my back expectantly. Ali put her fingers into her vagina to extract some fluid and wiped it carefully on my knob. Sita gave a self-conscious chuckle and then arranged herself on her knees with her small brown breasts resting on my thighs. This was exactly what I liked the most. Although tempted to close my eyes and simply die in ecstasy, I kept them open and looked at this blessed sight: two gorgeous women, one mature and one a young adult. Ali was comfortably upholstered with a nice covering of soft, freckled flesh and those wise, caring brown eyes. Sita was several shades darker, gloriously Asian, or so it seemed to me, as I had never even kissed an Indian girl before. Her hair was long, black, and silky, and her body long and slim. I enjoyed the sight of the top of her head as she went down on me: that geometrically straight parting and smooth scalp speaking of her general pristineness. She was, if not straight out of the box, certainly in mint condition and well cared for.

She took me into her mouth slowly and carefully. I didn't know how much sex she had had in her developing adult life, but I would have bet it was not much. You start off with instinct and learn through experience. My cock was in the mouth of a beautiful girl, and she clearly liked it.

Ali's intense expression told me she wanted some of this Sita action. The girl was apparently not the novice we had thought he was, and Ali wanted that skilful, enthusiastic tongue in her private parts. Anyway, I couldn't cum in Sita's mouth or anywhere else at the moment or I would be out of the game for a while, so I pulled out of that beautiful blowjob and said, "You can lick Ali."

Sita sprang to the task with such alacrity that it was clear she had been looking forward to this. She was naked with an older woman whom she liked, and that woman had stimulated her with her fingers. Now she got to nestle her face in Ali's crotch and consume some woman fluid. This was something Sita had never done before. It just hadn't cropped up over the course of her five years of sexual activity. Not that she hadn't thought about it. There was something nicer about a woman's body than most men's. The attraction of the male of the species was more to do with accepting their lack of smoothness, even embracing it. Political correctness these days made it appear wrong to even compare the experience of a rough and ready man with the silky charms of a girl, or, she shivered at the thought, a fully-grown woman. Sucking a penis and enjoying having a man pin you down with his sheer bulk and determination were natural features of being a girl. She didn't know if that changed as you got past 20. but an older woman had some of that assertiveness that was so much a part of being fucked, and she did like being fucked.

She also liked giving a blowjob. She didn't know if she was much good at it, but it seemed that as long as you enjoyed it, the boy would too. The younger ones, of course, were not in control and would shoot their silly stuff at the drop of a hat. But she had just sucked her male boss's dick and it had been lovely: a civilised act of mutual admiration. She had given him a good time while loving the slightly submissive part she played, and he had respected her good nature. He had stroked her head and squirmed a bit as if he was at her mercy, dependent on her for this intense pleasure.

Now she was about to lick Ali. Cunnilingus. She'd had it done to her by a few males, but all fairly inexperienced until ten minutes ago when Vic had given her a kind of royal treatment which would have made her gush into his mouth if they had had time. She was going to approach going down on Ali in the same way.

With her face between Ali's thighs, she smelled woman, and it was similar to her own brand. When she got her tongue in there, though, it was more mellow, less spicy than her own. But then she stopped analysing and making mental notes. She was having her first girl/girl encounter, and she loved it. She licked and sucked at Ali's lips and got as far in as she could, loving having the juices on her face and the aroma in her nose. Sally was squirming just like Vic had, but with even more abandon. She might be on the verge of cumming. Sita hoped no one was going to say their time was up. She took a split second to glance in Vic's direction and saw he was transfixed. He was almost as involved as she and Ali were, sitting there cross-legged with his hand on that beautiful, hard erection, which she wanted inside her ASAP. But not before she had sucked Ali's excited nectar from her quivering cunt. Cunt, she thought. People used it as a term of abuse, but it was a real word for the female sexual area, that warm, wonderful place where she could happily spend her whole life if it was always as good as this. Ali was spreading her thighs and then clamping them to Sita's head. Now she was gibbering.

"Oh my god, oh my god. Oh I'm cumming." And then she convulsed, smearing Sita's face even more with her grateful pussy.

It was a triumph for Sita, and she felt like the queen of the world.

"Now Vic is going to shag you, Sita," Ali announced. "Get on your knees."

"Can't I lie on my back?" the girl asked, only half joking.

"All in good time," Ali said, also half joking. I knew what she was setting up: she was getting Sita's lovely brown arse in position so I could worship it. Sita adopted the position, and I moved in and kissed her buttocks. She obviously wasn't sure what was going on, but she trusted us - so far. When I put my tongue to her tawny, crinkled hole, she actually spoke.

"Ah," she said.

"You like it?" Ali asked.

"I think so," she said quietly, so I increased the intensity, licking her strongly and lasciviously. I felt sure she understood.

While I was giving Sita her first rimming, Ali got underneath me on her back like a mechanic sliding under a car and sucked me. Then somehow the two of them bundled me onto my back and Sita was straddling me, fitting her crotch over my helpless cock, making it up as she went along. Ali was standing, wobbling, with her legs wide apart as she gave Sita her pussy to lick.

This couldn't last long; it was as impractical as it was clever.

"Fuck it," I said. "Ali, I'm going to shag her like you said, then I'm going to cum in you." And then I could leave them to finish up, cementing their relationship in a splurge of female juices.

Ali got the message immediately and sat on the bed. Sita flung herself onto her back with her legs apart and lifted to welcome me. I plunged into her, and you could tell she didn't know what the hell was happening to her. She was getting fucked and it was chaotic and messy and incredibly exciting. She surrendered herself to the orgasm that ran through her like a train. She was panting and giving little cries as she wrapped her legs around me, gave me a final squeeze and then disengaged and pushed me off so I could fuck Ali. I only just made it into Ali's drooling cunt before my own orgasm took over and I was pumping semen in where I had done so many times before, but never so urgently.

As I rolled off, the girls sprang together and kissed desperately. And then Ali made her way down Sita's glistening body, sucking nipples and poking her tongue into her navel as she went, before finding her home between those slim, firm thighs. She chewed and slurped at Sita's labia and sucked her clitoris until the girl came with an operatic wail.

I climbed on top of them and we laughed uncontrollably at the achievement of something we could never have stage-managed. Something magical had happened = something out of our control.