The moon wasn't always white, you know
Luna eyed the rock, her loins stirring.
Did she really want to do this?
It was, quite literally, the line she had drawn between sanity and insanity. From the moment she first saw the rock, she knew it would be difficult to resist temptation, and hastily drew a circle around it. If she crossed that circle, she would be unable to stop herself from violating that… thing. So for years, she didn't.
If she did, Luna knew everything would fall apart. Until now, she could pretend to be sane. Pretend that the decades of solitude did not affect her. But after that? There would be no pretending. She would no longer be able to convince herself she was sane.
Because no sane pony would ever, ever make passionate love to a rock.
The idea had first formed about 20 years ago. Or was it a couple weeks? She was no longer quite sure. It had taken her a while, but she had finally tried masturbating on the moon. Under normal circumstances, she never would have lowered herself to do something so base, but these were no normal circumstances. She had run out of things to do, and needed something different.
At first it felt great. Part of that was undoubtably all the arousal and temptation she had been hiding for the last couple hundred years. But the novelty quickly wore off. It began to feel more like a chore than anything. It was clear that if she actually wanted to enjoy this, she would have to change something. Spice it up. Add a new element.
It dawned on her that she was surrounded by new elements. Each rock could be a toy. Each rock could be hers. Each rock could be her lover.
Her mind accepted this so quickly and readily it scared her. She was beginning to think of the rocks as fellow citizens of the moon. She didn't want to let this happen. If she could continue to remember that the rocks were inanimate objects, she could keep a relatively firm grasp on her sanity. She was sure of that.
It became more and more difficult, though. Unconsciously, she would catch herself talking to the rocks. She would imagine seeing them move. Reacting to her. But most of all, she continued feeling that lust. As she walked to the moon's surface, she would start to size the rocks up, judging which ones would fit inside her, which ones would give her the most pleasure.
That was how she found the rock. The rock she had drawn a circle around. That was the perfect rock. It sent shivers up her spine whenever she looked at it, imagining the screaming orgasms it could give her. It was the perfect size, the perfect shape, and it even looked phallic. The sexual imagery hardly mattered to her, but what it represented, memories of being among the living, did.
She passed by it nearly every day, nearly salivating each time. As time went on, she became more and more enticed with it.
Today she felt she could contain herself no longer.
Her sexual arousal was at a peak. Thinking clearly was difficult. She could hardly go two thoughts without thinking of something erotic. It was sickening, but she longed for the days when she raped, literally raped, the old castle. She went to great pains to touch every inch of it, every brick. Spray as much as possible. Her drive was so strong Celestia and her guards could do nothing but watch. Walls collapsed, ceilings buckled under her pressure. It was one of the first things she did as Nightmare Moon. It started off being about revenge, but the pleasure quickly took over. She came so passionately so many times in so many places. She could hardly believe the sheer amount of fluids her body was excreting.
That was what she would do to that rock if she got the chance.
She remembered what she did in people's dreams. She could make a normally calm sleeper jizz all over their bed if she wanted. Even before she became Nightmare Moon, she took a perverse pleasure in sleeping with ponies in their dreams. It was one of the things her and Celestia had fallen out about. After she became Nightmare Moon, the sheer level of debauchery she pushed them to…
Luna noticed she had one hoof inside the circle.
She tried to step out, but her nethers twitched. She froze. If she took one more step, moved at all, she would probably come. It was unavoidable, she could feel it.
If she was going to come, she might as well get the pleasure she had been waiting so long for.
She stepped in the circle.
She panted. Her tail perked up, as did her wings. She could hear their motion disturb the ground a bit. Her horn spurted out some intermittent magic.
It was so close. She could feel it. She needed to act now.
Not wasting a moment, she lifted the rock with magic. She aimed it behind her. She raised her rear end, preparing for penetration, her tail excitedly waving back and forth.
She jammed it into herself.
She buckled to the ground almost immediately from the pleasure. It tore through her body, making her shiver and convulse. She moaned loudly. Her cum seeped out. Yes. Yes, this was it.
But it was not nearly enough. Not yet. As soon as the wave of pleasure died down, she started grinding the rock, humping it, jamming it in deeper. It was so big. She could feel herself tightening around it, feel it caressing all of her most sensitive spots. She went faster, and harder. She was building up. The waves of pleasure were getting stronger. She could hear the rock cracking.
Then it broke. She broke. Her world became blank except for the most intense pleasure she could remember. Her body convulsed wildly as she screamed and drooled and ejaculated with fervor unknown to her. It lasted for much longer than she thought.
Afterwards, she lay on the ground, panting, fondling herself. There was no need to hold back any longer. She could do whatever she wanted.
She looked behind her. At least a 5 yard section of the moon, including her, had been covered in her cum in the throes of her ecstasy.
She crawled over and began to lick.