When we got home from the movies the house was all quiet. Her parents had left one lamp aglow on the little table next to the staircase. They always left it on to ensure their daughters would not stumble on the stairs whenever they came in late. It was an orange, soft and vaguely glowing lamp. Its light wasn’t strong enough to reach over to the far end of the living room. It was a huge living room, and the lamplight reached only halfway across, so that a kind of soft orange screen lit up at the end of our field of vision, behind which was darkness.

That evening, during dinner, she had told me a peculiar story. Two weeks ago she had returned late from a party, and she had stood still at the foot of the staircase because a sound had alarmed her. She had heard kissing noises. They had reached her from the dark end of the room, penetrating the orange screen: slick, sloppy sounds of lips pressing and parting. And she had heard a whisper, a very sisterly whisper in fact, a breathy vibration in that very familiar voice that belonged to her sister Marion. Or had it been her other sister, Vanessa? She had not been able to tell, for the whisper had been unfamiliar too: it had sounded almost like a moan, and she had never heard either of her sisters moan before, she had not known her sisters ever did moan. But unless her ears had deceived her, that night she had heard one of her sisters moan and kiss.

For a while she had stood there all frozen at the bottom of the staircase, with the hairs of her neck and arms upright like those slender mammals that raise themselves up on their tails to scan the area. Finally, she had gathered courage and had stolen to the middle of the room, almost to the edge of the light, listening. She had heard the soft slap of skin on skin. A returning sound, a rhythmic slap of skin on skin. In that moment, she had felt her nipples piercing painfully though her bra and shirt. (When later she told me this story, as I am telling it to you now, the hairs on her neck and arms had once again stood up, and her nipples had, much to my delight, equally hardened.)

She had flushed all over and had instinctively started turning backwards, to steal quickly to her room, in order to remove her bra and contemplate what she had just heard, but unfortunately in her backward movement she stumbled against the low table, fell flat out on the carpet and made a huge noise. In a haze of panic she had then run up the stairs to her room, pressing her back against the cold door after she had closed it.

As I said, she had told me that story during dinner that evening, and so when I saw that orange lamp that night, I couldn’t help but think of the kissing sounds she had described, and I believe she thought of it too, for she lingered while unlacing her shoes, and we both peered across the room to the orange screen at the end of our field of vision, and I presume we both longed to have a sloppy, wet sound reach us from the darkness beyond.

I turned off the lamp. Darkness flooded the room, the staircase and the hallway. She had been down on one knee to untie her shoelace and she whispered to me from below: ‘What?’

I heard the anticipation in her voice.

I put my hand on either side of her neck and kneeled in front of her to get my face level with hers. I moved my lips to her ear and said: ‘What sounds did you hear that night?’

Against the palms of my hands, I could feel the heat race though her neck.

‘They were… kissing sounds.’

‘How did they sound? Like this?’ I said, whereupon I immediately placed a wet, almost sopping kiss on her ear. The arousal had made my mouth water, and as I proceeded kissing her I didn’t even have to try to make the sloppy sounds she had described in her tale, for it was impossible not to produce them.

‘Ye-es,’ she said.

‘And that other sound, that other thing, what was that, what did that sound like?’

Now, she shook her head. She began to stall, to evade the question, she began to play the wallflower, feigning innocence. Again I asked her. She said she couldn’t answer my question, she simply couldn’t describe the sound, couldn’t mimic it, couldn’t produce it. For the life of her she couldn’t and I had better be kind to her and believe her.

I refused her plea. I put her the question again and again: ‘What sound did your sister make? Say it. Make it.’

But she kept shaking her head, feigning innocence, saying she couldn’t. It was too lewd a sound, a sound that… well, maybe it was a sound all right for her sisters to produce, who were older than her, but it certainly was much too lewd for her, the youngest one, oh it was much too wrong a sound for her to make.

I became very excited. Her constant retreating and pleading, in short, her feigned weakness, aroused me intensely. Nevertheless, I hesitated to continue. I did not know how to continue this game. We weren’t green, we’d had sex before, but in a very vanilla, under-the-sheets, missionary, teenager kind of way. We had never really talked in bed to each other before, not like this, we’d never played roles. But now clearly something new had emerged. Now, she was playing the innocent, pleading to be let off the hook. And I was commanding her, refusing to let her off the hook. I believe I wanted, instinctively, to increase this feeling of dominance, I wanted somehow to intensify the urgency and desperation of her pleading. I felt this dormant, erotic intelligence waking up within me. But the only thing I could think of, was to stand up. And so I did: I got up on my feet, towering above her in the darkness.

‘You will make that sound,’ I said in a hoarse voice.

‘I can’t,’ she pleaded once more. It was breathtaking to hear her vocalise a sound with her face so close to my crotch. I felt myself become very, very hard. My heart was racing so fast I felt like I could faint, and my ability to think was severely diminished. I could do no more than make my voice sound even lower as I said, ‘Yes you will.’

It was too dark to see, but I think she shook her head, and in doing so, moved forward on her knees just an inch, because I suddenly felt her cheek bump against my crotch, and the very next thing she put her cheek and her mouth against my erection: through my linen trousers, she must have felt the hardness very distinctly against her face. And then – whether by design or out of sheer instinct or pleasure, I do not know – but amazingly, she made the sound, the sister sound: she moaned. It was the soft, breathy moan of someone who is tentatively trying out a new noise.

‘Again,’ I grumbled.

She moaned, louder this time, like a woman taking a hot shower in a guesthouse, somewhat cautious to be overheard.

‘Again,’ I grumbled.

She now pressed her mouth very firmly against my erection, then moved her head sideways, caressing me with her cheek, and as she did so, she let out a moan the way a woman moans with pleasure when she gets under a hot shower in her own house, with no one there to hear. Immediately after this, she murmured in her normal voice, ‘This is so hot.’

‘Yes,’ I said tenderly, in a sigh of pleasure. Apparently, we felt the need to intermingle our roleplaying with normal, tender talk, as if to let each other know we were still there and enjoying it.

‘Take it out,’ I grumbled then, returning to my commanding voice.

She let out a sigh, a moan; she really had the sound down now. The tingles went up my spine as she unbuttoned me, and pulled down my trousers and underwear. Since my cock had felt like bursting through the cotton and the linen, it now sprang free with such zest, that I felt it slap against her face.

How amazing she was, for she simply let it lay against her face! She didn’t touch it otherwise, didn’t kiss it, didn’t put a finger on it, as if she had no clue what to do with it, as if she just didn’t know what to do with it unless commanded by me. What she did do, however, was make the sound again, the sound so newly discovered, the sound she had so recently learned from her sister, either one of her sisters, her wonderful older sisters. Yes, like her moaning sister, she moaned.

Tingles ran over my spine again. I was so hard against her face. I was on the verge of commanding her to take it in her mouth, to blow me as she sat there on her knees in the dark hallway, God knows I was even on the verge of cumming all over her face on the sound of the very next moan she might make – but instead of any of all that, the lamp went back on. In an instant the orange glow reconquered the room. I looked to my right: on the staircase sat both Marion and Vanessa. Vanessa had flicked on the lamp, her hand was stretched out towards it, her eyes were wide with amazement.

At the sight of her sisters, my girlfriend raised herself quickly on her feet, but in doing so, her face and chest brushed against my erection, making it bob up and down, and I saw Marion look at it intently as she smiled and said: ‘Oh, excuse us!’

Vanessa flicked off the light. It was dark again, but not quiet. We heard them scuffle up the staircase, giggling like crazy. Only one door upstairs opened and closed, and I imagine they both went into Marion's room to throw themselves on the bed and giggle some more.