I have to admit I was a bit pissed to have to turn Tim down when he invited me to Starbucks after school. We’d only been dating for just over a week, and it would have been really nice to spend a bit more time with him, but I really had to get home to look after the twins.

They were fourteen now and had their own keys, but they couldn’t be trusted to get a wholesome meal for themselves yet; given half a chance they would happily live on cookies and juice.

My mom and dad both worked at the local hospital and tried hard to arrange their shifts so that one of them was around when the kids got home from school. But sometimes, like this week, they both ended up on nights.

It was hard to stay annoyed because looking after Madison and Matthew, or Maddy and Matt as they were always known, was generally a real pleasure. They are an incredibly rare thing: identical twins that are different sexes. They were both very beautiful: blonde-haired with delicate features and huge, expressive, almost cartoon-like, eyes.

Identical twins start off as a single egg cell and it’s sometimes said that therefore they are a single individual split into two bodies. that definitely seemed to be the case with this pair. I asked Maddy once what it was like to be an identical twin and she said that Matt made her feel whole, ‘it’s like he’s my other half’. I got a huge lump in my throat and welled up when she said that and had to give her a big hug.

When they were very young they shared a bedroom together. They were always put down in their own beds but, by the morning, they were invariably to be found cuddled up together in one bed or the other, which was absolutely adorable.

When they got older they hadn’t taken it at all well when they were told that they had to have separate rooms. But even then, sometimes they ended up in the same bed. It wasn’t anything sexual, they just didn’t seem to be happy unless they were in physical contact with each other.

If they were gorgeous when they were young, when they reached the age they’re at now, they became simply stunning. She grew more lithe and slender and his chest was just starting to fill out nicely. They both had asses to die for and her little breasts, in the tight T-shirts she normally wore, made my mouth water, and actually my pussy sometimes.

I felt a little guilty when my body responded to them that way, but I explained it to myself that it was exactly that: just my body liking what it saw. It’s not that I went out of my way to perv on them or anything, but then I never looked away either.

When I got home they weren’t in the house, so I went into the garden to look for them. As I passed through the patio doors I saw them coming out of the summer house. My dad had built it for them when they were toddlers and they had helped him with their little plastic hammers.

When they were young they’d spent hours in there playing mummy and daddy with her dolls, but I hadn’t seen them go in there for at least a couple of years now, and I wondered what they’d been up to.

“Hi guys, watcha’ doing?” I greeted them as they ran towards me and gave me a hug. That was one of the other lovely things about them, they were always so affectionate.

“Hi, Paige. Nothing really,” Matt said. I gave them each a peck on the top of the head and they ran off into the house, probably in search of more juice.

I went into the summer house and found that a blanket had been spread on the floor which, when I felt it, was still warm. It may have been my imagination, but I could have sworn that I could smell that distinctive odor of sex in the air. I put it down to two hot, pubescent, bodies and tried to forget about it.

The twins got out of school three-quarters of an hour before me, so they would have had plenty of time to get up to all sorts of mischief. I decided that tomorrow I would bunk off my last class and come home early. I opened the thin curtain just a crack so that, if they were in here, I’d be able to see what they were doing.

Sure enough, when I got home the next day there was no sign of them anywhere. I crept up to the summer house and looked through the crack. Maddy was kneeling with her back to me, and I could see that she had a toy stethoscope in her ears. Matt was lying in front of her and all I could see of him was his bare legs poking out to the right and his, also bare, upper half to the left.

Ahhh, I thought, they’re playing doctors and nurses; not surprising with my mom being a doctor and my dad a staff nurse. They could be so cute at times.

Then I saw the pile of clothing to their right and began to wonder exactly how thorough an examination she was giving her brother. I had my answer when she got up to move around to the other side of him. He was completely naked and his little penis was semi-erect. I felt a strong tingle in my pussy, and I couldn’t help myself, I put my hand down to squeeze it through my jeans.

When she had settled herself on his other side she proceeded to touch the end of the stethoscope to various points on his penis and balls while saying something to him that I couldn’t hear. Each time she did this his penis gave a darling little twitch which had my pussy fairly buzzing as I looked on.

It was still quite innocent and adorable and my hand was now rubbing firmly up and down. I was torn: I thought I ought to put a stop to it before it went too far, but I also really wanted to go on watching. I was still fighting with myself when Maddy sat back and folded her arms, and then Matt stood up and started to get dressed.

I gazed at his beautiful white bottom as he bent over to pick up his clothes and then again when he went to pull on his briefs. My pussy was decidedly damp and I had to drag my eyes away before sneaking back into the house. I waited hidden in there until they’d emerged, before coming out through the doors to greet them as usual.

Today was the last day of my folk’s night shifts so I knew that the twins’ time alone together was over, for the time being at least. I decided to put their antics down to normal children’s experimentation, but to keep a close eye on them.

Over the next few days, they seemed to be behaving pretty much as normal, possibly with a bit more whispering to each other than usual, but nothing really.

On Saturday afternoon my mom told me that she and Dad were going shopping for curtains and asked if I would look after the twins. I agreed and immediately thought that this would be a good opportunity to find out exactly how far their experiments were going.

I found them in the garden playing on their phones. As I started talking to them they stood up and then drifted together, putting an arm around each other’s waists. This was an unbearably cute habit that they got into years ago that never fails to make me well up with affection for them.

“I need to go and see my new boyfriend, Tim,” I told them. “Are you two going to be alright on your own for an hour?”

“Sure, Paige. We’ll be fine.” Maddy assured me. I gave them each a peck on the cheek and went into the house. When inside, I actually went upstairs and watched them from my parent’s bedroom window.

They stood talking for a few minutes before going into the summer house. I gave it a few more minutes, to be sure that they weren’t just going to come straight out, and then went down and peeked through the window.

I gulped as I saw that this time they were both naked: Maddy was lying on her back on the blanket and Matt was kneeling next to her tickling her armpits. She was wriggling around like a mad thing and giggling her head off. I couldn’t see Matt’s penis at this stage and still thought that it was pretty sweet. I also found it very, very exciting.

As I continued to watch, Maddy flipped over onto her front and, to start with, Matt resumed tickling her pits. Then his hands started to move down her body until he was tickling the cheeks of her little ass. I thrust my hand down the front of my trousers and started to rub my pussy as I watched him playing with her lovely bottom.

I knew I should have been thinking about stopping them but it was still fairly innocent and it was so fucking hot! I couldn’t get at my pussy as I wanted to with my trousers done up, so I undid the button and tried to pull the zip down. It had gotten snagged so I looked down while I freed it. I put my hand back inside my panties and could now slip my fingers inside me and it felt so good. I looked back through the window and was shocked to see that Matt was now lying lengthways over Maddy, supporting himself on his arms, and he was sliding his, now fully erect cock back and forth between the cheeks of her ass. She was still giggling like a maniac and had a huge grin on her face.

I knew that Maddy had started her periods some time ago and he was dangerously close to fucking her!

I pulled my hand out of my panties, did my trousers up, and then went and stood outside the door. I didn’t want to burst in shouting and frightening them, it might scar them for life and give them unhealthy complexes about sex. I decided to play it as cool as I could under the circumstances. I took a deep breath then I opened the door.

Both of their adorable little faces lifted up to look at me, and there was the same mixture of surprise and guilt on them both. They simultaneously turned to smiles as they saw that it was just me coming in. I could see the tip of Matt’s penis peeking out of the valley between Maddy’s perfect little cheeks and I felt wetness flood my pussy. I could also see a puddle of cum in the small of her back. I honestly thought it was the most erotic sight I’d ever witnessed.

I went in and shooed Matt away and then knelt down beside Maddy.

“Let’s get you cleaned up shall we?” I said to her very softly.

With a tissue from my pocket, I mopped up the sperm from her back. Matt was sitting cross-legged on the other side of her with a dewdrop of cum leaking from the end of his, now softening, cock. I tried to ignore it but it wasn’t easy, my pussy was soaking now and throbbing madly.

Then I saw that there was more semen in between the downy cheeks of Maddy’s little ass. The tissue was sodden now and I thought long and hard about using my hand to wipe it off. In the end, I used a corner of the blanket but I could still feel the gorgeous curves of her bottom through it, as I cleaned her up.

“That’s better,” I told her and patted her gently on the bottom, only just resisting the urge to stroke it. She got up and then sat down next to her brother and in the same pose.

They looked at me expectantly. It was really, really hard to keep looking at their faces and to keep a stern look on my face. In my peripheral vision, I could see her beautiful little vulva and his precious, soft penis and I just wanted to stare and stare at them.

“You really shouldn’t be doing this you know,” I said to them both. They looked at each other and, by some unspoken communication, Maddy seemed to be elected spokeswoman.

“He was only tickling me,” she explained. “It was fun.” She said it very quietly.

“I want you to promise me that you won’t do it again.” Again they looked at each other before turning back and nodding to me.

“Alright then, we’ll say no more about it. Get yourselves dressed and I’ll make us all some pancakes.” Their little faces lit up and the awkward moment had passed.

I left before they started dressing. I was so horny by that stage that I didn’t trust myself around them any longer until they had some clothes on.

I watched them carefully for the next week and they were as good as gold.

The following weekend my parents had to fly out to Florida for my Aunt’s funeral. I told Tim, and we arranged that he would come over after the twins were in bed. What with one thing and another, we’d only been out on one proper date and we hadn’t fucked yet, it wasn’t that I didn’t want to, it was just that I didn’t want to do it in the back seat of his car.

I hadn’t told him, but I’d decided to let him fuck me tonight. Mom and Dad wouldn’t have been happy with me but, with any luck, they’d never know.

I gave him a ring when I thought they were asleep and he got round here in record time; maybe he’d guessed what I had in mind.

We sat on the sofa with a couple of beers and started watching the film ‘Birds of Prey’. I thought it might be a good compromise of superhero crap without the muscle-bound crap, but Margot Robbie got Tim all excited, and soon he started to slide his hand along my leg and up under my skirt.

I was watching his face carefully as he did; there was a nice surprise waiting for him. His expression was priceless. He looked like ... well he looked like a boy who’d put his hand up his girlfriend’s skirt and was probably expecting to have it slapped away, instead he finds a naked, bald, and quite wet pussy and a big smile on her face.