A/N: There was ONE problem with this story: I did not know how to end it. Maybe there's more problems, but I didn't notice.

Phineas and Ferb, Danville's most wonderful boys, sat under the tree in their backyard. It was their daily ritual for brainstorming new projects as the two had a one-sided verbal conversation about what to do. Phineas, the red haired one, looked at his pet platypus that joined them.

"I wonder what it would be like to be a platypus." Phineas wondered aloud. His step-brother looked at him. "I mean. Wouldn't it be nice just to explore the world in Perry's eyes?" The more he said, the bigger his forming smile was. His smile was then the largest it could be. "Ferb! I know what we're gonna do today!"

Cue montage music!

As the two boys finished, they stared at their marvel, proud of their work.

"With this, we will be like Perry and we will walk in his shoes." Phineas said with a giggle. "Sounds exciting." Phineas pushed a button on the remote before the beam hit the two.

Doofenshmirtz Evil Incorporated

Doofenshmirtz was in his bed, still asleep from an exhausting activity. He inhaled, snoring loudly.

"Mimimimimimimi." He said as he exhaled. He inhaled. "Mimimimimi." He exhaled. He then started to speak in his sleep.

"Platypus… Marijuana… Vanessa… Prosecution… Judge Monobrow…"

Outside of his room, his "son," Norm, was looking around at his "father's" lab. He noticed one of his "father's" inators too close over the edge of the balcony.

"I'll just move this away from there so it wouldn't fall over. Father will be pleased with me when he wakes up." Norm said in his cheery voice. As he wrapped his arms around the machine a purple beam fired as he accidentally activated the machine. "Whoopsie." He said before moving it.

Back at Phineas and Ferb's house.

As the beam from Phineas and Ferb's machine disappeared, two new platypi stood in front of Perry. Perry looked at the two, shocked but showed no emotion to them.

Phineas had red fur and Ferb had green fur. Phineas was all smiles and Ferb was just as emotionless as he normally was. Phineas and Ferb stood on their hind legs, looking at each other.

"Oh man, this is so cool!" Phineas exclaimed as they examined themselves. They fell on their front legs, walking up to Perry before a purple light engulfed the former humans spontaneously. Perry jumped back, purely out of instinct, before the light disappeared like their green beam. Perry wanted to break character, to examine the boys for any abnormalities caused by the beam, but he didn't. He remained being the mindless pet.

Phineas and Ferb appeared to be perfectly fine.

"Ferb," Phineas said in a shaky voice, "I feel weird." Perry was concerned. He knew that the light was one of Deefenshmirtz's inators that hit them, but which one? Phineas looked at Perry with an odd look in his eyes. It scared the teal monotreme, but he composed his guise of a mindless pet.

Ferb watched his step-brother crawl towards Perry before the pet was pinned by the red furred platypus. Perry broke his guise for a moment to look at his owner in confusion. Phineas didn't know what was going on. Urges that he couldn't control nor understand were born inside the innocent platypus. He stared at his pet's bill, intoxicated by the sight before he dove in, connecting his bill with Perry's in a kiss. Phineas didn't know what he was doing, but his body craved his pet beyond comprehension.

As their bills locked, Perry looked at Phineas with wide eyes as Phineas' eyes were closed. Perry knew what happened to the two, but wondered why Ferb was unresponsive. He wanted to fight back, to push him off, but it would blow his cover as a mindless pet and would have to relocate.

He was forced to pick the lesser of two evils.

Phineas' body pressed itself against his pet, feeling his arousal grow and pressing against Perry's groin. He moaned before inserting his tongue into Perry's bill, tasting Perry's mouth. Perry couldn't help but moan as well, feeling Phineas' hard member pressed against his body, his sensitive parts, aroused him too. Perry thought that it was all wrong, blushing under his fur in shame and embarrassment and arousal. Phineas thrust his hips against his pet's warm member to satisfy his instincts, breaking the kiss and holding his head up as he humped his platypus before moaning again.

"Ah!" The two moaned. Even though it was happening, Perry still couldn't believe it as Phineas continued to hump him, frotting his pet. Both members were leaking pre come. Perry's was leaking on his pubic area as Phineas' was leaking on the member underneath, slickening his movements to force Perry to grab onto Phineas' fur tightly as the humping made odd noises. The two of them continued to moan as Phineas' instincts guided the two into great pleasure. "Ferb- Ah! This- Nng. Feels great." Perry looked behind Phineas, noticing Ferb's erect arousal between his legs.

Ferb crawled over to Phineas, extending his green furred hand to grab Phineas' tail, lifting it up to reveal his entrance. A small blush formed under Phineas' red fur as he watched his silent step-brother do this, feeling his rear end exposed. Ferb then pressed his bill against his optimistic step-brother's entrance.

"Ferb," Phineas asked, "What are you-? Ah!" Phineas' question was interrupted by a warm wet object, rubbing against his sphincter. He knew that it was Ferb's tongue. It felt so dirty, yet so good. He moaned softly as the tongue lapped him up before probing him, entering his hole and wriggling around. "Oooooh… Ah!" It felt so good. The bundles of nerves in Phineas' hole being touched and probed by something so wet, so slippery, was a pleasure indescribable to him. Ferb grabbed Phineas' fur on his back as he continued the treatment.

Meanwhile.

Candace was laying on her bed, waiting for her boyfriend, Jeremy, to call her like he promised yesterday. Her patience diminished quickly as she was bored just waiting. She sighed as she sat up on her bed.

"I'm bored," she complained, "I'm gonna go see what Phineas and Ferb are up to." The moment she looked out the window, she wished she hadn't. She saw an odd machine in the backyard, very bust worthy, but then she saw a red platypus mating with Perry and a green platypus licking the red platypus' rectum. She couldn't hear anything, but she saw their lips forming moans as the red one's bill moved to form the word, "Ferb." She then thought that her brothers are perverts who wanted to fuck Perry, so they changed themselves into platypi to legally have sex with him. Even she couldn't believe that. She turned around, away from the window. "Nope." She said as she walked away. If it was an illusion, it'd prove that she's mad, if it wasn't and she told her mom, she'd think she's beyond crazy. It'd probably be best to leave it alone.

Meanwhile again.

Isabella, Baljeet, and Buford were walking to Phineas and Ferb's house to see if they needed help inventing something. As they walked closer, they heard moans increasing in volume.

"What's going on over there? Is that… Phineas?" Isabella asked the two boys as they crept to the backyard, recognizing the moans. They peered over the fence, so they wouldn't disturb the moans, to see a really shocking sight.

"Hey, that red platypus is fucking Perry and that green platypus is licking the red one's asshole." Buford said in a slightly amused whisper so he wouldn't disturb the two.

"Are those… Phineas and Ferb?" Baljeet asked. The three stared for a few seconds before Buford took out a video camera, slowly, recording everything they're seeing. Isabella and Baljeet looked at him with horrified and disgusted looks on their faces. The two of them looked at each other and Buford looked back, his video camera still recording the events that took place in front of him.

"What?" Buford asked, completely bewildered by their stares.

Back to the boys!

Ferb finally stopped rimming Phineas, resulting in Phineas halting his thrusting motions in confusion at the lack of pleasure.

"Awww…" Phineas sounded disappointed. "Why did you stop?" Ferb answered by mounting his brother, pressing his leaking penis against the entrance. Phineas squirmed slightly, it felt really odd. Phineas and Ferb looked into each other's eyes as Ferb communicated to him in his language of silence. Phineas understood and nodded. "I'm ready. I don't know what's going to happen, but I trust you." Ferb's face was still blank before he pushed himself inside the red platypus that pinned the teal one. Ferb's eyes were clenched tight as he intruded Phineas' hole, inch by inch at a slow speed, feeling the sphincter tightened around the green platypus' member. Phineas squeezed the ground, feeling a burning sensation inside as a few tears fell out from the pain.

Ferb stopped. The moment he saw those tears, he stopped. Phineas looked at him with a soft smile. "I-I'll be fine." He said to his step-brother. "It's nothing." Didn't look like nothing but when Ferb was sure that Phineas was okay, he slid himself inside a little more. Phineas moaned a bit in slight pain before Ferb inserted himself in all the way, his green balls touching Phineas' red balls that touched Perry's teal balls as he finished his insertion.

Ferb waited for Phineas' cue to continue. He was given a nod before Ferb pulled out slowly. Phineas moaned softly, it felt odd as he exited slowly until the tip before pushing back in.

"Oh…" Phineas moaned. Perry watched as Ferb humped Phineas, feeling aroused and disgusted with himself as wet noises were made. Phineas continued his humping against his pet, moaning softly before he felt the intruder hit something inside. "Ah! F-Ferb. Right there. Hit me there again." Phineas begged before Ferb hit that spot again. "Faster…" Ferb complied, humping him faster as Phineas humped Perry.

It lasted for a while before Phineas felt an odd feeling in his groin. "Ferb… I feel something strange inside." Perry's eyes widened as he let out a few moans. He knew that it means that Phineas was going to come and Perry was close too. The three were breathing hard, making rhythmic breaths as they continued their act. Perry didn't want to come, to do something shameful in front of the two that were controlled by one of Doofenshmirtz's inators. "Ferb… It's getting stronger." The three were getting closer. Phineas finally made his last thrust, moaning as the strong feeling expelled into bursts as Phineas and Perry came.

Phineas looked down to see himself expelling a white liquid from his erect member. "Sorry, Perry. I- Ah!" Phineas couldn't stop himself from coming no matter how hard he tried as the two covered Perry in their semen.

"Ugh." Ferb could feel Phineas' hole clench him as he ejaculated with their pet. Ferb made his final thrusts, feeling orgasmic pleasure as he came inside his step-brother, shooting short thick ropes of semen deep inside.

"Oooh…" Phineas felt weird as his hole was overflowing with come, some of it leaking from him. The three panted as they finished, riding in the afterglow as their muscles relaxed. Ferb pulled out his shrinking member, letting the rest of the liquid from Phineas' entrance leak out. "What…" Phineas panted. "What just happened?" Phineas looked down at his mindless pet with worry as he noticed the white fluids all over him. "Perry! I'm so sorry, are you alright?" The mindless pet just chattered. Phineas hugged his pet out of clear concern, pressing the liquid against themselves. Phineas was confused. He did something that felt really good and he didn't know why and then he shot this sticky white liquid from a part of the body he uses to go to the bathroom all over his pet. He fell asleep on him in exhaustion before Ferb was falling asleep on his back.

Meanwhile.

Buford continued to record the events, looking pretty amused now. "Ho ho!" He exclaimed. "A drama scene. This is gonna look good on PPP." Isabella and Baljeet looked at Buford again.

"PPP?" Baljeet asked. Buford looked back at them.

"Yeah, Perverted Platypus People. It's a site platypus lovers go. I think I'm gonna be famous there with this footage." He looked at Baljeet as he answered before looking back at the site when he announced that he's gonna be famous.

"Is this even legal?"

"More legal than NAMBLA."