Just the emerald

Rouge reached inside the safe and removed her prize, a yellow Chaos Emerald. She admired it for a moment, how it glimmered in the light and had a faint glow. It was glorious.

Taking her prize she strutted back beside Tails, "Look at it, isn't it wonderful!" she exclaimed.

"I guess…" he replied in a dower tone.

"Don't be a sore loser, now. Or you won't get your reward," her attention lowered to his penis, still erect and twitching.

The thought of ending things so soon annoyed Rouge, she was having a surprising amount of fun teasing the fox, but the way he looked he was not going to last another ten seconds with her.

Looking at the emerald an idea popped into her mind.

"Let's give this a try!~" she carefully lowered the gem towards the head of his penis.

"Hey, be careful with that!"

Just as the stone touched his dick, there was a blindingly bright flash. Rouge shielded her eyes, and Tails looked away. After a moment, the bright light dulled and the two could finally see what had been done.

"Oh my goodness!~" Rouge delighted.

"No way…"

The two of them stared in bewilderment at his crotch. The two-inch penis which was on the verge of release had been replaced with a massive and girthy erection.

"W-what happened to my penis?!" Tails asked, in shock.

"Looks like you got an upgrade," Rouge licked her lips taking hold of the shaft. She gave its length and quick stroke and was astonished at how firm it felt in her hands. This wasn't an illusion, this was the real thing!

"Rouge, we need to be careful! There's no telling what effect that had on me!"

"I certainly know the effect it's having on me," she smirked, "I want to ride that thing until it's raw!"

Immediately she began undressing, throwing aside her boots, chestplate, and even her bodysuit until she was standing over his erection completely naked. Tails could hardly believe his eyes, it was as if this were some kind of dream.

She took hold of the head of his penis, and aimed it towards the lips of her labia,

"You ready?" she asked.

"S-sure."

Rouge lowered herself onto his penis, carefully she slid her way down until the entirety of his cock was inside her. Tails bit his lip as the pleasurable sensation worked its way down his manhood.

Having reached the base, Rouge takes a moment to delight in the sensation before rising up and then lowering herself down in a rapid repetitive motion.

Tails fought to remain composed as Rouge rode him harder and harder. He began to feel less like her sexual partner and more like a dildo she was riding. All the while, the building pleasure of their interaction starts to show its limits.

"R-Rouge…" Tails moaned.

"Shhhhh!!"

"Rouge, I feel like-"

"I said shhhh!!"

"But-"

"Stay quiet until I'm done!"

She kept riding him, drinking every moment as the fox beneath her struggled and strained. It had been years since she had ridden a dick this good, and she wasn't about to have Tails ruin that for her.

"I-I'm!!!!"

"Tails! What did I say?!!" she growled.

"I-I'm cumming!"

"Wha-?"

With one mighty thrust of his hips, Tails shot his seed directly into Rouge. It was like a volcano of hot warm semen launched into her, immediately knocking her out of her fantasy.

Tails collapsed flat on the ground in exhaustion. Rouge hopped off of him, causing his flaccid cock to slip out of her. His semen was practically pouring from her.

"Damn it…" she cursed, "You better not get me pregnant you stupid fox!"

To her annoyance, Tails didn't hear her as he was fast asleep with a satisfied smile spread on his face.

Looking down at his penis it was flaccid, though still bigger than usual. Even now she felt somewhat drawn to it but stopped herself from indulging further.

"Stupid fox…" she rolled her eyes, "Next time I'm bringing condoms…"

Rouge redressed herself and left the workshop with her prize, curious to explore the effects of the emerald again another day.