“Ah-Ahh...” Twilight let out an exasperated sigh. She had asked Spike to boost her to up to reach one of the higher shelves of her library, but when his claws dug into her flanks she felt... strange. Though visibly nothing had changed, a distant echo of something familiar, somehow forgotten, burned beneath the seamless flesh between her legs and underneath her tail.
“Twilight, are you ok?” asked Spike, struggling to hold the as-yet-wingless mare, while fighting to maintain his balance on the step-ladder. She wasn’t heavy, but something about the way she had shifted her weight was making it a bit more difficult to hold her up.
Twilight, realizing something was wrong, instructed her helper to let her down. “Sorry Spike.” she said as he stepped backward, only to have his legs buckle under him, an odd and electric sensation flooding his crotch. It felt as though his body was trying to supply power to some phantom tower.
They fell the short distance to the floor together, Twilight’s rump landing improbably on Spike’s face, drawing from her an embarrassing moan that made her eyelids flutter and her thighs contract involuntarily.
Spike’s muzzle was completely buried in her behind, the sudden pressure of his like a needle to the hoof, reverberating throughout her body.
When sense returned to her mind she promptly rose to her hooves, turning quickly around, nearly knocking away the stepladder, to check on her assistant. “Oh, Spike! Are you okay?”
Spike was not. He wasn’t injured in any way, yet he was fearful of the fact that he enjoyed his brief time beneath Twilight’s soft, squeezable-
He sat up and shook his head to clear it. “I’m fine, Twilight. I don’t know what happened.”
Twilight looked her companion up and down, vaguely aware of him clawing at the air in front of his crotch. Had he always been so cute? He didn’t look any different, yet...
A rush of feeling she was not prepared for came on like a warm tide and she couldn’t decide if she wanted to curl up inside herself, or explode into a million pieces. Maybe both.
“Something isn’t right.” she said at last, and saw relief flash across Spike’s adorable face.
“You feel it too? I was afraid....” he trailed off, his train of thought lost in Twilight’s evening eyes, possessed of a depth and tenderness that he had never seen, (or perhaps never noticed,) before now.
Meanwhile, the burning sensation below her belly was becoming too much for Twilight. Acting on instinct, she abruptly sat down, leaning back slightly and spreading her legs as she tried to suss out what her body needed.
Twilight’s flushed cheeks and vulnerable pose made Spike’s head feel numb. He kept on distractedly swiping at his crotch, as if trying to grasp something that wasn’t there.
Why isn’t it there? thought Twilight, looking up. “Where did it go?” she said under her breath.
“Where did what go, Twilight?” asked Spike, his eyes drawn to the the empty space between her legs. It’s not supposed to be empty. he thought, uncertain of what that meant.
“I don’t remember....” Twilight followed the heavy feeling downward, searching for the epicenter.
Seeing her like that, sitting on her tail with her hooves in the air, awakened an instinctual desire within the young dragon. He felt the urge to be near her, getting down on his knees and shuffling close.
Twilight had ceased paying him any mind, focused on tracing the feeling to any physical abnormality, and finding none. “Don’t worry, Spike.” she said without looking up. I’ll figure somethiii-ahh!”
Spike, unable to help himself, began to gently stroke the invisible seam that ran from her crotch to where her tail began.
“What are y-you.... What are you doing! Spike!” Somehow he had discovered something; something strange, and also wonderful.
“Is it helping?” asked Spike, pausing to look up at Twilight for a moment.
Why did he...? thought Twilight angrily. “Don’t stop!” she shouted, then backed down at his look of surprise. “I’m sorry. Please, Spike, keep going. It’s like a terrible itch! I’m begging you!”
Somehow hearing her call his name made him feel... acknowledged? It was nice, anyhow, yet still that invisible rod throbbed and he could feel a building tension that desperately craved release.
Spike resumed, but Twilight didn’t seem to be getting any relief. Perhaps if his talons could satisfy the ‘itch....’
“Ouch! Don’t scratch me!” squeaked Twilight, although it wasn’t entirely unpleasant.
“Sorry, Twilight. I don’t really know what I’m doing.”
Twilight let out a shivering breath. “Me neither.” She thought for a moment, trying to recall something she wasn’t quite sure she ever knew. “Try... licking, maybe?”
Spike wasn’t expecting that. “Lick you?” he asked, imagining himself running his tongue along her coat.
“It’s not that weird!” Twilight countered desperately, thought somewhat unprovoked. “A-and you don’t have to look so disgusted.”
Spike blushed and looked away. “I-I’m not disgusted, it’s just... this is all so new and so...” He struggled to find the words. “When I look at you, I want to be close to you. Part of it is that I want to help you, but another part wants... I don’t know.”
Twilight saw him scratching between the legs, and felt guilty. She wasn’t the only one craving relief.
Spike was looking around at everything but her, giving her time to lean forward and press her hoof against his crotch when he moved his claw.
“T-Twilight-!” A shiver went through him, and it felt as though warm water was rushing through his body, easing tensions he didn’t even know he had.
Twilight looked up at his contorted face, and their eyes met briefly, the both of them confused and desperate. Then he pressed his lips against hers and they embraced, pressing and rubbing against each other with the uncertain eagerness of baby birds testing their wings for the first time.
Unseen, a rubric that no pony remembered having ever been cast began to fail.
Author's Note
Here is a tiny bit of feverish scrawl. What happens when you need your genitalia but they aren’t illustrated? How well does that concept translate into the written word? We’ll see, I guess. 
