A/N: This is my first fanfic. Constructive criticism is fine. There is some content in this chapter that some readers may find rather disturbing. You have been warned!

It was a summer weekend in Danville. The two famous inventors were sitting in their house while a summer storm raged on. Phineas had just turned 16. Ferb had turned 16 three months ago. They had both gone through puberty enough to know some certain things that happen to the male species.

Phineas turned to Ferb and said, "Hey Ferb, do you wanna go and see the gang for a while?" Ferb just smiled and nodded. Phineas liked it when Ferb was so quiet. He found it somewhat... sexy. It turned him on. Phineas had started finding Ferb hot when he was 14. He had started dreaming about Ferb and him together at night, and them getting intimate. Ferb collected the tool box and he and Phineas went across the road to get Isabella.

While they were crossing the road, the storm picked up ferociously. Lightning was striking the city of Danville. It was not a pleasant sight to Phineas. Ferb had the tool box over his and Phineas' head. Lightning hit the path in front of them and they jumped back, surprised. Isabella opened her front door because she saw the two stepbrothers crossing the road. As Phineas and Ferb got across the road and started walking up Isabella's driveway, lightning hit the tool box. Phineas and Ferb both felt an electrical surge go through them. They both collapsed in front of Isabella.

"No! Phineas! Ferb!" Isabella shouted as she rushed over to them.

Phineas woke up to the sound of Isabella sobbing. Isabella felt the couch move and turned to look at Phineas.

"Ferb! You're awake! Thank god, I was worried for a minute there!" Isabella said, obviously relieved. "Isabella, it's me, Phineas!" said Phineas, confused as to why Isabella would call him Ferb.

"Sense of humour back already, is it, Ferb?" said Isabella, grinning. "Isabella, please understand, I'm not Ferb, I'm Phineas!" said Phineas, starting to realise that his voice was different, and had a thick British accent. Then, Ferb woke up.

Isabella was so relieved to see "Phineas" awake. "Phineas! Thank god! For a minute there, I thought you had died!"

"What are you on about? It's me, Ferb!" said "Phineas", realising that his voice was higher and with an American accent. "You are joking, right Phineas?" said Isabella, slightly worried about what might have happened. Phineas looked to Ferb, and Ferb looked to Phineas.

"AARGH!" they both screamed simultaneously. "I'm in your body!" said Phineas in Ferb's voice. "And I'm in yours!" said Ferb in Phineas' voice. All of a sudden, a thought creeped into Phineas' head. "I just need to go to the bathroom." said Phineas. And he ran to the bathroom.

Phineas closed and locked the door behind him. Since it was probably his only time to do this, Phineas opened the zipper on Ferb's trousers and pulled his pants down.

PEOPLE WHO GET SQUEAMISH EASY AND/OR FIND THIS DISTURBING TURN AWAY NOW!

Phineas stood there, looking at Ferb's penis. He gently started to rub it, and it started to get hard. He stopped rubbing and stood there, looking at Ferb's now erect penis. He then continued rubbing at vigorous speeds. He started to moan and he got a lovely feeling through his body. Then he stopped. He couldn't take advantage of his brother this way. But he continued rubbing. Then he started to masturbate. He felt good doing this in his body, but in Ferb's body, he found it awesome. Semen started to eject out of his penis. Phineas heard a knock at the bathroom door and quickly wiped the semen off of Ferb's dick and pulled his trousers up and opened the door.

ANYONE WHO TURNED AWAY CAN NOW LOOK BACK!

"Phineas, are you ok, you've been up here 20 minutes." said Isabella. "I'm fine, I'm just going to go home now." Phineas said, willing Ferb's erection to go down quickly.

"Ferb, are you coming home?" asked Phineas. "Yes, yes I am." replied Ferb. Phineas put the tool box over Ferb's head and his own head and they walked out the front door.

As they had finished crossing the street, lightning hit the tool box again. Phineas and Ferb felt a huge electrical surge go through their bodies and then they collapsed on the floor, unconscious.

Phineas woke up. He immediately looked down at himself and cheered. He was back in his own body. When Ferb awoke, he cheered too. The two stepbrothers immediately went into their house, just as the storm calmed down.

A/N: Did you like it? I always wanted to do a story where Phineas and Ferb got to know each other more intimately, and a body swap story just came into my mind. Reviews will encourage me to write more stories.