I think almost everyone thought this after Space and Time. Just an alternative version of it, very explicit, and M for a reason.
The TARDIS shook madly, shuddering through the time vortex. In the console room, the Doctor took dancing steps around the control panels, sometimes, tentatively, pushing one of the buttons or levers. Often it did little except make the ride even bumpier.
"Temporal turbulence!" he called out, to a mostly sceptical Amy and Rory, pulling down harshly on another lever. "Just like clouds in an airplane, only not clouds and not in an airplane. It makes everything wibbly! Hold on!" The Time Lord shouted the last two words, tottering back before falling forwards onto the console, pulling down the switch which normally made them land.
The engines gave an almighty groan, whole ship shuddering, straining against something. The Doctor winced, patting the console tenderly.
"There's a paradox in our future," the Doctor called out to his companions, not turning around. "That's what's causing this, a huge, wibbly wobbly paradox. Very soon in our future. We're going to have to ride through it, the old girl can't stand corrupted time like that."
Oblivious to what the Doctor actually meant, Amy tightly gripped the railings. Rory was close to her, holding on tightly also, feet lifted up off the ground with each violent shudder. The Time Lord leapt with each step, struggling to stay in control of his movements.
"Rory!" the Doctor shouted, turning his head over his shoulder, "I need your help, hold this down and try not to explode."
"Explode?" Rory blinked, tentative. The Time Lord shrugged.
"Possible side effect, almost impossible. Well, mostly. Well, kind of, well, fifty- look, doesn't matter, just hold the lever down and I'll try to pull us out of the turbulence," the Doctor was flung almost a metre into the air by the shaking time machine, grabbing hold of another switch as he landed.
Nervously, Rory approached the central console, struggling with each step, just managing to get to the centre. He exhaled in relief, wincing as he pulled down on the specified lever, holding it down. The engines groaned.
The Doctor hit a row of buttons, Rory gritted his teeth as he held the lever down, and Amy clung tightly on to the shuddering rail; and then, with an almost deafening rumble, the whole TARDIS shook from side to side, Rory and the Doctor thrown violently away from the centre, only Amy staying in place due to her tight grip.
"Emergency protocols!" the Doctor yelled as he was thrown away; he brushed one switch just before being forced away, hitting the wall and falling, unconscious to the floor, beside the similarly out-of-it Rory.
Amy, the last one conscious, let go of the railings in relief, the quaking stopped; the engines grinding. Turning, she froze.
Like before. It must be the emergency protocol the Doctor had shouted about, landing the TARDIS in a safe place while he waited to wake up. The TARDIS had chosen, again, the safest place: inside herself. An oh-so familiar blue box materialized near the front doors of the time machine.
The redhead was about to react when the doors to the time machine around her opened. With a glimpse of a golden room beyond, Amy tensed to see a figure walk through; fairly tall, with long, vibrant red hair, in a short skirt as always, and... It was her. She couldn't bring herself to be surprised. Her own face looked towards her, an odd smile on her lips; her face was flushed, eyes a little glazed, and sweat was just visible, reflected off her forehead and cheeks.
"Ok, kiddo," the second Amy smirked. "This is where it would get complicated if we hadn't been through it all before. landed in the safest place, drifted forwards in time, and..." she shrugged. "You've already figured it all out. I remember. And yes, you still really look like this. And that paradox the Doctor detected is just about to happen. As you'll say, an event that caused itself." the future Amy paused to catch her breath; already panting. Definitely worn out.
"Do you... even know what any of that means?" the first, past Amy said slowly, carefully stepping down until she was closer to her future, now-smiling self.
"Not at all. Just remember you or me seeing it." she laughed. "I do remember something else though."
"Yeah?"
"Yeah. What you're thinking right now," the future Amy smirked. Past-Amy looked away for a moment, before looking back.
"You can't make me feel guilty, you thought it too."
"I know," future-Amy gave a maddening smirk. "And I did more than think."
Past-Amy blinked. A moment's silence; her eyes ran down her future self's body. Flushed, breathless, slightly sweaty. She wore a creased short skirt, a slightly torn top, a confident smirk, and her hair was pulled back, messed up. Oh wow.
"You mean, we..." Past-Amy's voice trailed off. Her future self smiled, and nodded, slowly striding closer.
"Those two," she gestured to the out-cold Rory and Doctor, "Stay out for, ooh, at least the next hour. Trust me. We have just enough time to find out all the things you're curious about, and do all that you wanted."
Amy's lips touched her own. her future self initiated it; her past self reciprocated with eager ease, hands running forwards, up her back, feeling all those curves, dips and bumps she never could reach. The redhead turned them around, the older Amy breaking the kiss slowly, pulling back, reluctant. Their eyes stayed on each other as past-Amy was lead up to the area of the floor nearer to the console.
Their lips met once more. Passionate, with so much promise. The younger redhead pressed her teeth forwards, lightly grasping her older self's lip, tugging gently, her hands running up the other woman's back, again curious as to all those bumps, ridges and soft dips. She pushed forwards, turning each other, the future-Amy slowly pressed back against the console.
Lifted up onto the edge of the console, away from the switches, the future-Amy broke the kiss, breathless, flushed and smiling as she looked down the small distance to her younger self.
"I know what happens next," the Amy sitting on the edge of the console smiled softly, breathless. The younger redhead met her eyes.
"Of course you do. Not something I'd let me forget," the younger redhead smiled, her hands softly on the other woman's knees. Gently, she spread those pale thighs, running her hands up them, towards the already damp underwear. She bit her lip; pressed a little harder, toying gently before moving her fingers, pushing those panties to the side and caressing past them, tantalizing; the sitting Amy arched her back, gasping.
It was strange, watching herself like this. Breathless and flushed, barely touched yet already so wet. There was only one finger inside her partner, but it knew exactly where to go, and exactly how to stroke, how to tease. The older Amy was moaning openly by the time a second finger moved to go inside her.
Two fingers now. On the console, the redhead arched her back further, hair cascading down as her head pressed against the central column. her legs were wrapped around her younger self, tightly, body quivering each time those two, those three fingers brushed one of those perfect spots.
Her younger self smirked, recognizing all the signs. She looked up at those half-closed eyes, those just-parted lips making indecent moans, and-
Stopped. Her future self widened her eyes, just an instant, unsurprised but disappointed at the instant's break. "Tease," she gasped, still breathless.
"You know it," the younger Amy met her eyes; and leant closer, curious, interested. She softly kissed the skin just below her body's breasts, and trailed down, towards the delightfully wet place her fingers had just teased. She wanted to taste herself now, curious; and what better way? She hesitated for a brief moment over that point, exhaling, breath tickling her future self's entrance.
"Please!" the sitting Amy gasped, desperate and breathless. The younger Amy smiled, again exhaling, once, still teasing. then, eager, she leant closer, tongue leaving her mouth to just brush her partner's clit, curling over, pressing gently.
She loved hearing the sound of her own moans. Louder and louder, her tongue drawing teasing circles around that delightfully sensitive point. Another smile. The redhead's tongue swirled once more, before dipping ever-so-slightly, tip beginning to move inside her future self's body, moving deeper within. She searched inside, delving deeper and inwardly congratulating herself each time she brushed one of those points she knew made her wriggle.
Amy smirked at a delightfully wicked thought: she tasted delicious.
The younger Amy closed her eyes, feeling her future self's hands run down over the back of her head, winding through her hair with fingertips digging in, desperate for more. Nails scraped the back of her neck, needy; she knew when she was closer. Amy's tongue delved deeper into her own body, loving how she tasted, loving how it felt to explore herself, and hearing the noises she made. So loud.
A much louder moan; almost a scream, as her future self tightened her grip, hips shuddering as her taste flooded the younger Amy's mouth. She swallowed it eagerly, relishing her own wetness; it seemed to go on for exquisite minutes, feeling her own body rock in ecstasy around her, legs wrapping closer, tightly over her shoulders.
It was almost a minute more, before those hips loosened, releasing the younger redhead, letting her straighten, standing up. She licked her lips, meeting her future self's eyes.
"I taste good, hm?" the future Amy panted, still breathless. "And I'm good with my tongue," she smirked for that last sentence, cocky.
"Really?" the past-Amy flirted openly. "I might need some proof of that."
"Go get it," from the console, the redhead gestured towards the TARDIS exterior, the model that had materialized within itself. "It's your turn now."
The younger redhead's eyes widened for an instant, before slowly smiling. A step back; then a leap forwards again, touching her future self on the lips, a gentle, then rough, kiss. A passionate farewell.
Amy Pond smiled broadly, flushed, walking back, eagerly rushing back through the doors of the box: to the past, and to ecstasy.