Ginny hurried down a corridor, biting her lower lip nervously. It was late, just after the final classes, and the halls were mostly clear. She was making a beeline for the Gryffindor common room as her hard shaft pulsed urgently against her stomach, barely hidden beneath her robes as Ginny rocketed around a corner, slamming into something and going flying back, her books and papers flying up in the air as she skidded to a halt on her ass, shaking her head and looking up in shock.
She went white as she first saw that her robes had slipped open to reveal the very obvious bulge in her trousers, her tip actually poking above the waistband, it was so hard. She slowly looked up to see who had caught her- and stopped short as she saw a similar situation across from her. Her eyes slowly moved upwards, taking in a slender, comely build, fair skin, blonde hair, and silvery-blue eyes… Luna Lovegood.
Luna gave that far-off smile she always did, calmly getting to her feet and dusting herself off, apparently uncaring of what looked like a raging erection between her legs. She walked closer to Ginny and held out her hand.
"Sorry about that, Ginerva," She said in a soft voice as Ginny wordlessly took her hand. "Here, let me help you with your things."
Ginny blinked, confused.
"But- Luna, you saw-"
"And you saw mine," Luna answered in that voice, standing back up with Ginny's books in her arms, still with that far away smile as she hands her things to Ginny. "Well, I'd best be getting back to the common room-"
Ginny rolls her eyes and stuffs her books under one arm, grabbing Luna's arm with her free hand and starting to drag her away, changing her course towards the Room of Requirement.
"We need to talk," She decides, giving Luna no room in the matter as the blonde girl didn't resist, but let herself be dragged away. She quickly found her way to where the Room was, and closed her eyes, concentrating hard as she muttered a phrase Hermione had taught her- one that would instantly open the room. Sure enough, the door swung open, revealing the interior of a small parlor with a comfortable fireplace.
She dragged Luna inside and the door swung shut, closing them into the cozy space. She bit her lower lip again, nervous now that she had the other girl in the small space. In all the commotion, her erection had tamed a bit, and stood at about half-mast as she wordlessly shrugged off her robes and dropped her pants, exposing her cock to Luna.
Luna mirrored her motions, dropping her own pants to reveal her own, fully erect, girl cock. Ginny estimated it to be about the same length as hers, a tad thicker and a little curved- and with a pair of testicles hanging below them, currently tight as they wanted to empty themselves.
"Luna?" Ginny asked uncertainly, feeling herself reach full erection at the sight of Luna's secret.
"Ginerva." She answered, that smile in place again, but her eyes seemed a little more in focus than they usually did. "I see… So we are a little different."
The door opened and Ginny spun around, staring as Hermione walked in, her nose buried in a book, dressed in a simple cardigan and jeans. Hermione looked up, blinking in surprise as she saw her girlfriend and Luna Lovegood, both with full hard-ons.
"It's not what it looks like!" Ginny blurts out, knowing full well what it must have looked like. "I bumped into Luna in the corridor and she, uh, well…"
"Ginerva and I ran into each other, and she spotted that we shared something unexpected in common," Luna says smoothly, giving that smile to the speechless Hermione. "She wished to talk about it more, so we came here. You walked in as we were comparing."
Wordlessly, Hermione walked forward, taking in the scene as she jammed her hands in her pockets, yanking out parchment and a muggle pen and rushing to an end table, immediately starting to scribble. Ginny relaxed as she recognized her lover's curiosity taking over, groaning as she sat in a chair, her relief sending her back to half mast. Luna daintily took a seat across from her, her own length not budging an inch. Ginny took in the sight, slowly realizing that Luna must be so hard it hurt…
Suddenly Hermione was in front of Ginny, taking her hand in hers. Her eyes had a spark to them, and she was flushed with excitement.
"Ginny, do you realize what this means? You're not alone!" Hermione sounded triumphant as she turned, getting on her knees before Luna, brazenly inspecting her member closely. Luna merely blinked and looked at her, tilting her head curiously.
Ginny felt her spirits rise to a new height as the news sunk in. She wasn't the only one who'd experienced this- she wasn't alone.
"Luna, may I inspect your, ah, other… end?" Hermione asked awkwardly, realizing the position she was in. Wordlessly, Luna climbed further on the chair, turning backward and bending over. Unlike Ginny, Luna had no girl parts, only the cock and a perfectly clean asshole. Hermione gasped appreciatively and went back to scribbling, noting down the differences. "So were you born with this, or…?"
"Yes," she answered calmly, even while bent over. "My mother theorized it was because of a peculiar type of wrackspurt that managed to make its way into her womb while she and my father were making me."
Hermione nodded and began scribbling again, noting it down as a possibility, but, as all things with Luna, taking it with a grain of salt. She finished her note taking and set down the parchment. "Alright, Luna, please sit down once more. May I… inspect the goods?"
Luna turned back around, sitting politely.
"I do not take issue with it, but perhaps it is Ginerva that you should be asking first."
Hermione smacked herself on the forehead, turning around to look at Ginny, who was smirking from her seat.
"Go ahead, Hermione," she said in a low voice, settling back to watch. She had little doubt that Hermione just wanted information, knowing the docile girl wouldn't even think of it as anything else.
Hermione bowed her head to Ginny, turning back to the matter at hand. She slowly reached out and grasped the base of Luna's shaft, noticing that it was unbelievably hard, a degree or so above Ginny's usual aroused state- perhaps something in the hormones, since their bodies were different. She ran her hand up her shaft, running a finger around the tip and observing how Luna reacted- her breathing sped up and she colored a little bit. Sensitivity, then, was around the same level as Ginny. Finally, there was only one more thing to test… Hermione leaned down and ran her tongue over it, backing off and standing up, concentrating on how it tasted. It was minutely different from Ginny's, but still along the same lines. She nodded happily and went back to her notes, leaving poor Luna in the chair, cock hard and the tip wet now.
Ginny swallowed, knowing firsthand how awful it felt to have a persistent erection. She knew Luna was holding back because she didn't want to interfere in their relationship, but…
"Luna," Ginny said slowly, gathering her courage. "Would… Would you like help with that?"