At the start of the summer break, our masturbation group left school forever. Unfortunately, the members were moving to different colleges all over the country, so the dynamic of our group had to adapt as well.

Steven and Jack were no longer a couple, so I'd suggested Steven and Thomas make a go of it as boyfriends. It seemed a logical step; they'd had sex before and enjoyed it, plus they were at colleges in neighbouring towns and could see each other pretty much whenever they wanted. I'd also offered to add a female dimension to their fun from time to time if they wanted it.

The snag was that I lived much further away from them both, so it took about a month to arrange their first visit to me. But by this time, there was an increasing sense that all of us worked well together, so our intention was to have a threesome. We'd done it before, but not for a long time.

By habit, watching each other masturbate was always part of our foreplay. But when we tried to have sex, it was impossible without making the bed squeak. I had five or six flatmates – the number fluctuated as students moved in and out – and at least one of them was usually indoors at any given time. We then tried it on the floor and on my desk chair, but those weren't very comfortable, so we stuck to masturbation.

It didn't help to go to one of their places either. Both lived in similar conditions, and they hadn't been able to have penetrative sex with each other.

Regardless, it was still hot; I never tire of watching boys stroke themselves in that uniform up-and-down motion, especially these two, as they showed such affection. I touched my nipples as they made knowing eye contact with each other, then used their free hands to rub each other's bodies, and kissed with tongues. Finally, I licked up Steven's semen, then he swallowed the load from Thomas.

A couple of weeks after that, Samantha drove me down to visit Tiff, who had moved the furthest away. We all wanted the boys to be there, but it would mean an overnight stay and there was limited space in Tiff's room, so it became a ladies-only weekend. The girls were still dating, but Samantha had a job and couldn't easily relocate, so they'd agreed to try out a long-distance relationship.

Almost as soon as we were in the bedroom, we undressed, brought out our vibrators, and began to touch our own clits.

For me, masturbating with the same sex is only a social activity because I'm not much turned on by other women, whereas doing it with males is erotic. As a lesbian, Samantha felt exactly the opposite. Tiff was attracted to both sexes, although seemed to prefer women.

I didn't comment on it, but I was taken by the change in Tiff's appearance. She'd cropped the hair on her head to no longer than an inch, but had let her armpit and leg hair grow. I saw one of her nipples had a bar pierced through it. She'd also shaved her pubic hair in such a way that her clit was more visible.

Samantha's appearance hadn't changed much, except she'd always had the largest nipples and clit in the group and they seemed to have increased in size. I couldn't last longer than two or three days without an orgasm, but she'd told me how she hadn't masturbated for a week and was so horny that 'I even fantasised about men'.

Since the two of them hadn't been together in so long, their masturbation quickly turned into sex. At first, I tried to be quiet because Tiff had flatmates, but she said, 'You hear sex happening here all the time: gay, straight, nobody cares.'

As I say, women don't turn me on much, but I'd seen them many times before and I found it interesting. They were keen to demonstrate their toys on each other. Samantha had brought a vibrator I hadn't seen before. This one was bendy; the larger part went inside Tiff and the smaller end could be angled to hit the sweet spot on her clit.

Samantha knew how to tease her girlfriend; sometimes she would get her off, sometimes she would withdraw it at the crucial moment. Tiff liked to pull on her nipple bar when she was about to orgasm. I couldn't imagine the boys teasing me or each other like that – they just wanted results. I would need to teach them.

As a result of their teasing and generally slow pace, these ladies could last for ages. I had time to bring myself to three orgasms before I felt the horniness subside. I seized the opportunity to let myself moan for once. I then took a shower, dried my hair, and dressed for bed – and at that point, they were only just thinking about stopping. I treated myself to one more orgasm as they finished up.

After the fun, the conversation turned to the subject I'd avoided so far: Jack. Unlike the rest of us, he wasn't going to college. Instead, he had an insane idea that he wanted to own a gym, inspired by some rich 19-year-old in the papers who had done just that. The major difference was that his idol had a rich family supporting her, whereas Jack didn't, but he simply wouldn't listen.

Then, at the start of term, Steven and Thomas had made an arrangement to leave on the same train. Tiff sent her best wishes as she'd gone by that time, so Samantha, Jack, and I went to wave them off.

About ten minutes before departure, Jack had casually mentioned to Steven that he was sorry they had to break up, but that he was sure they would meet other guys.

At first, we thought we'd misunderstood him. Steven had talked to him many times to agree when they might visit each other. As far as he and the rest of us were concerned, their relationship was still solid. But Jack had apparently changed his mind since then, as he went on to grandly declare that long-distance relationships don't work, like he'd ever been in one.

I'd never seen Samantha angry before, but she gave him what sounded like a painful slap and marched him away. And that wasn't even the half of it.

'Oh,' she sighed. 'He's gone downhill since slap day. Me and the family are really struggling with him.'

'Is he still on about that gym?'

'Worse. He's fallen in with a bunch of wasters, and he thinks they're great because they take him on drinking benders. Now he hasn't got school or wank group, he's lost the structure in his life. Blames everyone else for his mess.'

'He got in touch with Steven a couple of days ago,' I said. 'Did you know that?'

'Took him long enough. Did he apologise?'

'Um, kind of. It was one line.'

'Tell Steven if he hasn't answered already, then don't. Look, I hate saying it about my own brother, but it's all self-pity. He needs to learn he can't make a mess and fix it with a non-apology.'

'I hope you're able to help him.'

'I hope so. Anyway, that's depressing. What I want to know from our straight friend,' she stared at me, 'is how she enjoys having two boyfriends.'

'I'm sorry, what?' asked Tiff.

'You won't know,' I clarified, 'it's only just happened. You know how I suggested Steven and Thomas should try being a couple? Well, they're getting on well and we all think we have a vibe together, so we're trying it out: they're still boyfriends, and I'm the girlfriend to both of them.'

'Oh, wow,' said Tiff. 'You're a lucky lady.' Samantha coughed theatrically. 'And so am I. Have you had another threesome yet? Like actual sex, not just wanking.'

'We've only masturbated. We've all got flatmates, so we can't make too much noise. I wish they were open-minded like yours.'

'Wait until December,' said Samantha, 'everyone clears off for Christmas and you can have the place to yourselves.'

'Funny you should say that; me and the boys said exactly the same. In fact, I've been planning a couple of surprises for them.'

'Ooh, like what?'

I wish I hadn't said that. 'Just... things.'

'Yes, like what?'

I sighed. 'If I tell you, do you promise to keep it to yourselves? I don't want to spoil it for them.'

'Oh, we promise.'

I managed to meet up with Steven and Thomas a couple of times before Christmas but we still didn't manage to do anything more than masturbate.

Then in mid-December, just as Samantha predicted, my flatmates started to leave and they were all gone within a couple of days. I'd told my parents I would be home a few days later so I could meet up with friends; they didn't need to know the details, and they didn't mind.

I felt overjoyed to welcome my boys to my empty flat. I kissed them both on the lips and watched while they kissed each other. I'd laid off masturbating for two days and that vision almost sent me over the edge.

I'd poured out wine in the kitchen because I wanted to speak to them briefly first. 'So those surprises I talked about.' They looked me down at my lacy dress. 'Correct, that's one of them, but there's more.'

'Nice,' said Thomas.

'You know how I was on the pill?'

'And Thomas went bareback with you? That was amazing to watch.'

'You remember I asked him to pull out, though, because I wasn't sure about trusting it. Well, I've now talked to the doctor and got an implant instead. She said she would trust it, and because it's inside me, I can't forget to take it.'

'So you're saying...' he trailed off.

'What that means,' I paused for effect, 'is that I'd like you both to start spunking inside me.' I enjoyed saying the words, and I looked forward to the feeling.

Their faces lit up. 'That...,' started Steven, 'That's going to be amazing.'

'Now, I don't want to dampen the mood, but I'd like you both to keep using condoms with each other just now, just while you get checked out, and we'll talk about that some other time, all right?'

'All right,' they said, almost in unison.

'I've got one more surprise in me, and I'll show you while we have our fun. Do you want to start?'

They answered by standing up almost immediately, the wine barely touched. I linked my arms in with theirs and led them both to my bedroom. I shut the bedroom door, and we began kissing and undressing. I'd kept some towels aside for us. I gave Steven and Thomas one each and I unfolded mine and placed it in front of me.

Once all our clothes were off, we started masturbating as always. I switched on my vibrator.

Although we'd all watched each other many times, They didn't seem to notice the change I'd made to my stroking style. I now moved my fingers in and out of myself as I approached orgasm, much as Tiff did. I was glad they didn't pick up on that, as it might have ruined the surprise.

Without having to keep the noise down, I could let my breathing be heavy and even moan a little, which caught their attention. When I orgasmed, I spurted clear fluid, followed by a few smaller streams. Much of it landed onto the towel, although I caught as much as I could in my hand.

I showed it to the boys, who couldn't quite believe their eyes.

'What did...?' said Steven. 'Did you just squirt?'

I preferred a different word. 'I can ejaculate now, just like you. Let's taste it.' We all sampled the liquid from my hand and kissed again.

'How long have you been able to do that?'

'Well, I've known for a long time that women could do it, but I'd only been working on it since the start of term. It's only been in the last few weeks it comes out every time.'

I was still learning when I was with Tiff and Samantha. I'd only managed it on my third orgasm, which soaked the bed, but they were too busy having sex to notice.

Did you enjoy that?'

'Um, yeah. Definitely.'

'Does that mean you're one of the boys now?' asked Thomas.

'I suppose so,' I said. 'I wish it was like your semen, but there's not much I can do about that.'

'It still tastes nice.'

I moved closer to them. 'All right, my two boyfriends,' I whispered, kissing both of them again, 'let's have our threesome.'