Hey there! This is my first story so far, which I got the idea for when my dad was lecturing me about science, and I noticed that Capricorn could be the perfect nickname for Steve, and if you take away the r, it sounds like a cross between capsicle and a unicorn. So, here is my spur-of-the-moment story! I hope you enjoy!

Steve hated it when Tony spouted science lectures.

For one thing, he couldn't understand them, and for another, they put him to sleep. Or at least into a daze, depending on what it was about. This time, when Stark had caught him experimenting with some of the random things around the lab and looking at the shadows they cast, he had started off talking about something that seemed to involve tropics and not seeing shadows, or something. To Steve, it sounded like groundhog day in Hawaii.

"EARTH TO STEVIE! EARTH TO STEVIE!"

The super soldier jumped in his seat. "What?" He asked groggily.

"I'm talking to you, Cap! Pay more attention!" Tony yelled at him. "As I was saying, the other one is called the Tropic of Capricorn, and..." He stopped talking and looked thoughtful. "Hey, I've got a new nickname for you! Capicorn!"

Steve groaned. He didn't get the joke, but a nickname was definitely something to be afraid of, especially coming from Stark.

"I don't get it," He told the other man, who was still laughing.

"It's a cross between Capsicle and a unicorn! Ha ha ha, I can just imagine you with a horn and a mane and tail!" Tony howled with laughter. Steve, however, didn't find it amusing.

"I don't see what's so funny." The newly named Capicorn said stoutly. This just caused Tony to laugh harder.

"And at the same time, it references to the Tropic of Capricorn! It's perfect!"

Steve shook his head and left to kill some punching bags. In the training rooms he found Natasha and Clint there too. The archer was swinging around the ceiling beams, and the red head was cleaning her guns. Natasha raised a quizzical eyebrow as Steve came in and started brutally murdering the innocent punching bags, noticing the peeved look on his face. "What's wrong?" She asked.

"Oh, Tony came up with a new nickname for me, something about unicorns or something." Steve shrugged. Natasha sighed at Stark's immature behavior and went back to cleaning her guns.

Tony was still laughing when Steve—Capicorn—left. He was way awesome at giving people nicknames.

The billionaire started to get this itch, the one where you just have to play a prank on someone. Smirking, Tony got off the floor and started his planning.

Training always helped Steve vent his frustration, so he was feeling much calmer as he went back to his room. He opened his door, then stopped, horrified.

His room had blow-up palm trees and posters of half naked girls surfing. His floor was covered in sand and rocks, along with life-size unicorns. And when he checked his drawers all he found were Hawaii print shirts. Streamers were hanging from the ceiling, and if that weren't enough, there was a huge banner on his back wall that read:

WELCOME TO THE TROPIC OF CAPICORN!

Steve sighed.

"STARK!"