What do you mean there aren't any bushes around Dragon lands?
Author's Note
This story was inspired by SWikey, who gave me this premise. 
The AU tag is for Spike is aged-up/late teen in this story, while the story itself happens during the events of Season 6 episode "The Gauntlet of Fire", where Spike's age was more ambiguous.
What do you mean there aren't any bushes around Dragon lands?
Spike had no idea what he was doing. He had been summoned to Dragon Lands to take part in some trial called "The Gauntlet of Fire", which he had never heard of before, and now he was running like hell, chasing after a hidden Bloodstone specter that all the other dragons were trying get in their claws. Whoever could find it first would become the next ruler of Dragon Lands, the Dragon Lord.
Spike really wasn't interested of becoming the ruler, but he knew the future of Dragon Lands, and the whole Equestria, would be in danger if Garble happened to find the specter first. After happening to save Ember, the daughter of the sitting Dragon Lord Torch, he promised to help her proving her worth and save Dragon Lands from Garble's clutches.
Or so was the plan... The reality hit Spike pretty soon as he came to and open area in the canyon and found himself lost. He had been running to the wrong direction the whole time!
"Oh, heck no!" Spike cursed and scratched his head, "I should have turned left!"
He sighed in frustration and was turning towards the exit, but then he felt ache in his bladder. All that running had made him not notice he needed to urinate and now it was too late:
he needed to find a place to pee as soon as possible to prevent him for wetting himself.
"Oh man! Not now!!" Spike panicked and looked around the place, "I really hope there's some cover over here..."
He knew other dragons would ridicule him if they saw him peeing, or even worse, they could attack him in his vulnurable state! That's why he needed to find at least a small boulder or a bush to provide some shield.
"Oh, there!" He suddenly noticed a leafy bush in the back of the open and started running towards it.
Although, it was way too convenient. Why would such a bush grow in a barren canyon filled with lava springs and craters, of all places? It was very suspicious indeed... But for Spike that didn't matter, he was way too desperate for a sweet relief to think logically.
Yet he should have, because that bush was actually his friends in disguise!
Twilight and Rarity had arrived to Dragon Lands with Spike, disguising themselves as various objects to hide their presence while they tried to follow him around. Spike had seen their previous disguise, a giant rock with somewhat visible eyeholes, but after they got separated when the Gauntlet started, they needed to abandon their disguise and wear another, which was a bush. The very bush Spike was approaching at the moment!
"Spikey-Wikey!" Rarity gasped in relief, seeing Spike from behind the bushes leaves, "Thank heavens he's alright!"
"I told you not to worry!" Twilight replied and smiled, "He's way tougher than he looks!"
"I wonder if he knows we're here, Twilight," Rarity was a little worried , "Maybe he's worried that we've been exposed and captured by those beasts!"
"Well, he seems to be in a hurry," Twilight said and shrugged, "But I think he's good. We can't come out just yet. I'm certain Spike can smell us when he gets close, don't worry!"
"Hmm, smells nice!" Spike commented as he arrived by the bush. He looked around one last time to see if there were any other dragons around and then leaned closer to the bush. After flexing his abdomen to make his penis come out of his slit, he grabbed it with his claws and pushed it deep into the bush, hoping it's leaves could provide him some much-needed cover. He was all alone and he started to relax.
"Hey, Spike-" Twilight's words got stuck in her throat when she saw it, even Rarity couldn't say a thing: Their eyes shot open when Spike's turgid, pink dragon dong appeared before them in its full size, pointing menacingly towards their faces. They could only stare at it with their mouths open, not sure what was even happening.
”Oh my... Is that what I think it is?” Rarity whispered in awe and covered her mouth. Twilight on the other hoof grimaced, knowing very well what was about to happen. It wasn't the first time she had seen Spike's quite impressive phallus out like that (he was a teenage dragon with needs, after all!), especially in this kind of context. She was staring the thing right in the glans, noticing that Spike's urethra was expanding to make way for his impending relief. To her horror Spike's floodgates we're opening and she was standing in the way!
”Wait, Spike! We’re in-!” Twilight was going to shout, but it was too late to stop Spike. A warm trickle of golden urine shot out of Spike’s urethra and splashed against Twilight’s cheek, making her jolt. She moved her head in panic, making Spike's piss splatter into her open maw and on her tongue, making her almost gag. She quickly closed her mouth and swallowed, immediately regretting her choice. The acirid and salty taste of Spike's amber nectar wasn't exactly the best thing she had tasted in her life, having gotten it in her mouth once before when she had helped her mother to change Spike's diapers, but she didn't let out a sound, trying her best to not reveal herself and Rarity.
”Mwaaaaaaah!!” Spike sighed loudly. He closed his eyes and leaned his head backwards, enjoying the feeling of his piss surging out. He let go of his junk to stretch his arms for a while, letting the gravity take hold of his piss-stream. His twitching member leaned freely at Rarity's direction, splattering his stream on her chest as she stared at it in the mix of adrupt horror and arousal. Spike's piss streamed down her body as if he was pissing in an urinal, coloring her alabaster coat with a golden yellow tint. She moaned quietly into her hooves as she felt it brush on her clitoris.
”Huh? There must be some kinda rock inside!” Spike wondered aloud as he felt his droplets splashing back at him, but he shrugged and continued to go like it was none of his busines. He started waving his dick from side to side as he went, hosing both mares with his warm piss. Rarity's mascara ran down her cheeks as her face was completely drenched and Twilight squinted her eyes as tightly as she could. She was preparing her horn laser to zap Spike in defence, but she stopped after she felt Spike's stream becoming weaker - finally!
After Spike was done, he sighed in relieve and shook himself dry, flinging his droplets across Twilight’s and Rarity’s faces. They wanted to scream, but they couldn’t, it would have been too embarrassing at this point anyway.
After a brief pause when they opened their eyes in unison to check whether their ordeal was finally over, Spike gave his cock one last hard shake, sending some excessive droplet into Rarity’s eye and snout. She let out a quiet whimper in disgust, but luckily Spike couldn’t hear it.
”Aaaah, so much better!” Spike said in satisfaction and let go of his member. He turned around and wondered where Ember had left. ”Okay, gotta run quick before Garble finds the specter!"
***
”Ok… That was uncalled for!" Twilight said with an unamused tone after Spike had zipped away. The sheer amount of urine Spike had produced was enough to drench the both of them completely.
”Oh no, my mane!” Rarity whined as she tried to wringe out as much of Spike's piss as possible, "It takes forever to get this smell off my coat!"
"Yes... I know..." Twilight replied. She was going to strangle Spike after this trial was over, "He might be tougher than he looks, but by Celestia not really that smart!"
”But I got to admit, darling…" Rarity smirked suddenly as she wiped herself with a handkerchief, a hint of lust burning in her eyes, "I couldn't believe Spikey-Wikey would be THAT well-endowned for his age! If he was a stallion, I would most certainly fall for him-”
She stopped talking after seeing Twilight glancing at her in disapproval, making her blush, ”Umm, I mean... Let us never speak of this again, darling!”
”Great idea!” Twilight replied, "Let's ditch this bush and follow him!'
"Splendid!" Rarity said cheerily, "I have made another great disguise just for this kind of occasion, absolutely stunning a rose bush! Why, the smell is simple di-"
"NO!!"
-THE END-
