It was a regular Saturday in Canterlot. The former student of Crystal Prep Academy, Twilight Sparkle, had been walking her dog, Spike, in the park in the early morning, and now they were returning home.

"What a lovely day, Spike!" Twilight said in excitement, "It's not too hot or cold today!"

"You said it, Twilight!" Her talking dog replied back, sniffing the ground for a moment, "And not too wet either! Rainy days make it hard for me to smell!"

"Glad you enjoy it too, Spike!" Twilight smiled, "It sure is gonna be a good day!"

After they had returned She unleashed Spike to let him run off to his dog bowl and went to the kitchen to make herself some coffee. She saw Spike taking only only a couple of licks of water before turning around to leave.

"Say, Spike..." She remarked, "Have you been drinking enough water lately?"

"Umm... Sure, I guess!" Spike stopped and replied, "What about it?"

"Well, I noticed your pee was very yellow this morning, which is a common sign of dehydration."

"Huh?" Spike thought for a moment. How did his owner know that in the first place? Was she looking under his tail while he was peeing? And if so, did she also do that often?

"Well, you see; urine has this substance called urochrome that causes the liquid to be bright yellow!" Twilight started explaining, "Drinking enough liquid will dilute that color, making its tint lighter. So albeit not lethal, having darker yellow urine usually means you're suffering from dehydration!"

"I have no idea what you're talking about, Twilight!" Spike replied in confusion as Twilight had, once again, forgotten she was talking to an actual dog!

"Oh, right..." She blushed in embarrassment, "It means you should drink more water, that's all! I'll just have to fill your bowl more often!"

"Okay, okay! I'll drink more water then, I promise!" Spike shrugged, not understanding why the very color of his literal waste product was such a big deal, "But... Does that also mean I can get outside more often?"

"Well, if you really gotta go, then yes." Twilight said, "I can take you out more often."

"Awesome!" Spike replied and shook his tail in excitement, "So if I drink more water, you will take me for walks more often?"

"Umm... Sure, why not!" Twilight smiled, "I think I need to go outside more often as well!"

***

As the day turned into an afternoon, Twilight leashed Spike once again and went on a walk with him. Walking in a nearby park, Spike was sniffing around like any regular dog did while Twilight tried to follow him. He soon found himself a good spot to mark and raised his rear leg, a heavy stream of urine erupting out of his urethra almost immediately.

"Aaaah!" Spike sighed in relieve as his urine cascaded down the tree trunk. While still going, he suddenly turned his head towards Twilight, noticing she was looking at him. But instead of getting offended by her breach of privacy, he started smiling evilly.

"Like what you see, Twilight?" He asked with a husky voice, making Twilight turn her head towards him.

"Oh, n-no! Sorry Spike!" Twilight replied in embarrassment, "I was just checking on you if you still suffered from dehydration-"

"Yeah right!" Spike chuckled, "You just like watching me mark my territory, don't you?"

"No, I wasn't staring!"

"Yeah, babe! Just watch me claim these spots as my own!" Spike shook his rear to make his testicles swing along with his sheath, making his stream splatter all over the tree, "See this dick, Twilight? I bet I'm a real alpha!"

"What?!!" Twilight was becoming upset, "Where did you learn language like that?!!

Spike didn't respond as his stream slowed down to a tiny trickle. He sighed audibly and shook his leg to get the excessive drops of urine off his sheath. Dogs didn't normally do that, but thanks to the magic of friendship, he had learned some new skills that even Twilight wasn't aware of.

"Aah, that felt good!" Spike sighed in relief and looked around the park for a moment, "But there's still many more trees to claim out here!"

"What?" Twilight called out in confusion, "You still got to pee?!"

"Yup!" Spike said boldly and walked towards a tree close to him, "This tree here is mine!"

He then raised his leg to mark it. Then he started walking to the tree on the other side of the road.

"And this one too!" He proclaimed and urinated on the tree's roots as well, then he kept repeating the process with yet another tree. A part of his penis was poking out of his sheath as he did it, a sign of him getting aroused by what he was doing. It made Twilight feel a little uncomfortable.

"Gosh, how much did you even drink?!" She thought to herself while she ran after her dog.

It didn't take long for Spike to mark all the trees around the area, and he kicked around his hind legs after he was done.

"Hah, now I'M the owner of this park!" He hollered at the peak of his masculine self-confidence, "Take that, Winona!"

"Ok... Maybe we should head back home, Spike!" Twilight smiled nervously. She saw Spike's cock swinging around as he shook his rump, but fortunately it wasn't completely exposed just yet. "You're getting a little too excited, don't you think?"

"Hey, Twilight!" Spike suddenly said and stopped, "You think Winona would like to see this thing?"

"Huh? What thing?" Twilight jolted and glanced at Spike, "What do you-?"

She then saw something she didn't want to see at that moment:

Spike's red rocket had slipped completely out of his sheath and was now leaning against the ground like a literal fifth leg!

"Aaaah! Spike!" Twilight screamed in an utter shock and closed her eyes, "Stop showing off your penis! Put it away!!"

"What now, Twilight?" Spike asked with a sultry tone, "What am I supposed to put away again?"

"Y-your penis, Spike!" Twilight replied in panic and started looking around the area, "Hide it before someone sees you!"

"Oh, this one?" Spike raised his rear leg, moving his crotch a little to let his erect member pop onto display, "You're saying I have to put it away, right?"

"Spike! Stop kidding around!" Twilight snarled at her dog, luckily a couple of feet away from him so she wasn't able to choke him to death, "You can't possibly go around with that- SPIKE, WHAT ARE YOU DOING?!!"

Twilight saw Spike having rolled on his back with his limbs stretch out and now he was taking his junk in his own mouth to fellate himself!

"H-how does he do that? Dogs cannot suck on anything, they don't have cheeks?!!" She screamed in her mind, unable to do anything but stand there doing nothing as her dog was giving himself a blowjob.

Spike pulled his dick out of his mouth with a pop, a trail of saliva connecting his tongue and the tip of his schlong, and then proceeded to rub it in front of Twilight. He glanced at her and smirked, "Didn't you just ask me to put this away? How else I'm gonna do that, then?"

He then stroked himself playfully to tease Twilight, making her squirm in embarrassment, "Or would you like to lend me a hand?"

"NO! That's it, buddy!" Twilight said angrily, "We are going home right-"

"Oh, hello Twilight!" Twilight suddenly heard one of her friend, Fluttershy, greeting her from behind, "Isn't it a lovely day? Are you and Spike on a walk?"

"F-Fluttershy! Don't come over here!" Twilight screamed in panic. She spreat out her arms, turning around to hide Spike behind her back, "And I really mean it! Do! NOT! Come over here!!"

"Why not?" Fluttershy replied in confusion, "Has something happened to-"

Despite Twilight's efforts of shielding Fluttershy's eyes from the horror that was Spike masturbating in the open, she had forgotten that she was taller than her. All she had to do was look a little past Twilight's shoulder and she was staring right at Spike behind her, waving his canine penis towards her direction.

"NOOOOOOOOOOOOOO!!!" Twilight's senses were screaming as she realized Fluttershy had already seen it. She was now traumatized for life, and she knew it was all her fault!

But instead, Fluttershy wasn't terrified. While she was visibly confused, she didn't look as shocked by the perverted display as Twilight had been afraid of.

"Oh... My..." Fluttershy gasped in surprise. As she had history of seeing animals behave weirdly throughout her life, she was more intrigued than traumatized.

"Um, Twilight..." She looked at her friend, "Why is Spike doing that? Have you done something to him?"

"What?! No!!" Twilight shouted back, "Spike's the one doing this! He's been acting weird this whole afternoon!"

"Yeah, I'm fine, babe!" Spike smiled and kept stroking himself, "Just giving my owner a good show!"

"Oh, I... I can see that!" Fluttershy walked past Twilight and blushed, "That's pretty macho, Spike! Your... Thingy sure looks pretty handsome-"

"DON'T COMPLIMENT HIM!!!" Twilight snapped at her friend, making her peep in surprise.

"R-right! Umm... That's... Not very appropriate, Spike!" Fluttershy stammered and gave Spike a stern look, "You know very well good dogs don't do that in public!

"Well, then I'm a really... Bad... Dog!" Spike chuckled, using his other foreleg to play with his knot. That act alone made Fluttershy's eyes shoot wider, and she subconsciously started biting her lip in arousal.

Precum leaked down Spike's scarlet shaft as he stroked it with his paw, and as Twilight and Fluttershy kept staring at him, he felt even more like being in control. He enjoyed girls staring at him while he did it, and by the smell of it, they both were as equally aroused by it!

He could hear Fluttershy moaning silently, smelling a lovely smell of arousal from her as she had become wet against the fabric of her panties. Her clit was aching, and she had a hard time trying not to put her hand inside her panties to rub it.

"Yeah, bet you like this!" Spike panted and lulled his tongue. His rubbing got faster and faster as his cock shook in his paw.
It didn't take long for Spike to feel his climax coming, hitting him like a meteorite. "Oh, dog! I'm gonna... Gonna!"

And right after saying it he closed his eyes and howled as his penis sprayed thick globs of dog semen into the air. It rained down on his belly and nozzle, coloring his body with strands of white all over. He even got some of it on his extended tongue, but he didn't care, he was way too lost in ecstacy!

After landing from his high, he glanced at the girls in front of him and smirked, still holding his twitching cock in his paw.
"Huff... Huff, t-that's right, bitches!" He huffed while he felt like losing the last of his strength, "I'm a real... Alpha...!"

He then lowered his head on the side and drifted in a post-orgasmic sleep, a perverted smile looming on his face. He felt so proud of himself at that moment!

"Oh my..." Fluttershy gasped in a weird mix of shock and awe and turned towards the embarrassed and seemingly very annoyed Twilight, "I think you should switch the brand of his dog food, Twilight!"

"Maybe..." Twilight sighed, mumbling behind her palms, "Or get that mutt outright fixed!"

-THE END-

Author's Note

So, I decided to do something different, meaning I've now written my first (and probably last) Equestria Girls story. While I enjoyed Rainbow Rocks very much, I'm not that fond of that series and I'm not familiar with the characters nor care about them, expect Spike (He's a dog so he gets a pass).

Anyway, this story is mainly written for a friend. Hope you enjoyed it as well!