A/N: Hope you guys enjoy! This is my latest idea for Derek and Penelope!
It all started with a bet about Esther.
After much debating over what to eat for dinner, they had decided to go out. Derek didn't have many food options to choose from, especially at his bachelor pad, so Penelope suggested Chinese.
They'd wound up taking her car instead of Derek's. He was usually the one to drive, as he hated how cramped Penelope's car was compared to his SUV. However, tonight she was insistent on getting to drive. "You're tired from the case," she said. "Let me take you in my car."
He had finally given in. He was reluctant at first, but he knew that Penelope wouldn't back down. Once she set her mind to something, she was hard to deter.
"Why couldn't we take my car?" Derek moaned once they were out on the main road. Esther seemed to struggle at the higher speed. "We're not going to make it to the restaurant at this rate, baby. The car is on its last leg."
"Don't say that about Esther!" Penelope yelled, petting the dashboard as if the car could hear. "She may be old, but she's gotten me through a lot. I've had her since I graduated from Caltech."
"Seriously?" he said. When she nodded, he added: "That's why Esther sounds like death. She's old! Can you hear that clunking noise? That's not normal!"
"Quit hating on my girl!" she chided. "Or you'll get no after dinner fun!"
He waited a minute before saying anything else. "I bet it's going to break down tonight," he said. "Twenty dollars if it does."
"Deal," she said, surprising him. 'I'm only betting because I know that Esther is basically immortal. If she was going to break down, it would've happened a long time ago."
"You're on."
They made it to dinner in one piece. Derek enjoyed his egg rolls and Penelope had her fun reading fortune cookies and giggling over them. "Luck is on your side, Hot Stuff," she flirted across the table. "I guess the cookie knows what we'll be doing later."
It was on their way back when the car died completely. They were about two blocks away, waiting at a red light, when the car just stopped.
When it wheezed its last breath, Derek cheered. "Finally!" he said. "I can stop worrying you're going to break down on the interstate or worse. That and I have lunch money for tomorrow. Pay up."
"What?" Penelope cried. She turned the key in the ignition, but the car was unresponsive. "You got lucky!" she insisted as she fished the cash from her wallet. "I'm calling AAA. There's no way Esther's life is over."
After that dramatic night with Esther (and yes, the car had survived once a mechanic took a look), they began having bets constantly. "I bet you could put ten spitballs in Kevin's hair before he'd notice," Penelope giggled. "The man is catatonic or something when it comes to computers. He doesn't notice anything off the screens."
"He doesn't have that much hair," Derek said. "He'd feel it."
"I swear," she said. "When he's on the computer, he's so preoccupied with all his programs that he doesn't know the time of day."
"He's going to notice, Baby Girl," he said. "There's no way he'll keep typing. It's not like Lynch has an afro."
"C'mon," Penelope said handing him a straw. "Loser buys dinner."
At that offer, Derek took position behind a plant near Kevin's desk. Making sure no one could see him, he started to fire at the geek's hair.
Sure enough, he made it to thirteen before Kevin noticed. His entire head was covered in little spit balls before the idiot realized his hair was getting wet. "What the hell?" he had yelled while Penelope and Derek ran off giggling like school kids. "Who did this?"
Next, Derek bet her that Reid had a crush on the new girl in Penelope's computing department.
"Look at the way he looks at her," he said. "Can you say love at first sight?"
She thought he had the hots for JJ still. "No way," Penelope said. "He still likes JJ. Always has, always will.
After much fishing from the genius, Penelope found out that he was head over heels for Jane. They even talked Reid into asking her out. "Just go for it, pretty boy!" Derek had told him.
"2 to 1," Derek reminded her later. "I'm in the lead."
Penelope bet that Derek didn't have the balls to dance on Hotch's desk while he was on a lunch break. "Everyone will see me!" he had cried. "What am I supposed to do if our new boss walks by? She's already on our case for all the flirting. I can't!"
"Chicken," she hissed at him. "If you don't do it, I get to show that receptionist girl all those pictures of you in chaps."
"Go for it."
"I'm not talking the photoshopped ones here, my friend," Penelope said darkly. "I'm talking about the real ones. Remember that drunken movie night at my house a year ago?
Derek danced on Hotch's desk. As soon as the words left her mouth, Derek was up on the desk moving around to an invisible beat. He was lucky most of the floor was gone to lunch.
It wasn't Hotch that caught him. It was Rossi. When the older man walked in, he took one look at Derek and held his hands up: "I don't think I want to know."
It kept going like that until the end of March. They had done everything they could possibly think of. Derek bet that Penelope wasn't brave enough to rollerblade through the BAU. Mostly, he wanted revenge for dancing on Hotch's desk and getting caught by Rossi. He'd been so embarrassed! He could barely look at the man for days afterward. Luckily, Hotch hadn't found out.
Penelope did what Derek said she wouldn't. She brought in her rollerblades the next day with a determined look on her face. As soon as the floor was mostly clear, she took off. She won that round. (Derek got his revenge though when she crashed into Kate's desk and Hotch came to investigate the noise.)
He only said: "I hope you two are having fun with all this. Rossi and I are certainly enjoying watching it. Just don't let the higher ups see you."
On the 31st, Derek tallied up their score. They were sitting in Penelope's office going through paperwork and needed a short break. "We're tied," he said. "We both have ten points."
"Damn!" she said. "How did that happen? I thought I was in the lead."
"Not since you failed to trick Reid into eating an escargot, you're not," he said. "We wound up tying. We'll have to break it tonight with the ultimate bet."
"Ultimate bet?"
"Yeah," Derek said, running a hand across his head as he thought. Then: "I got it. Whoever wins a round of Wii tennis at your place is the winner of all our bets. If we don't stop in time for April, Hotch and Rossi might kill us."
Penelope snickered. "That or Cruella will fire us."
Cruella was the name they'd given Strauss's replacement. Neither of them had bothered to learn her name, but they were definitely on her bad list. So they whispered jokes to one another about her and called her Cruella behind her back. That and the fire breathing dragon.
"Alright, I accept," she said. "We need a higher prize though. We've bought enough lunches, dinners, and gave each other twenty bucks to last a lifetime. Since this is the last one, it needs to be original."
They both thought for a minute.
"If I win," Derek started. "You have to get a tattoo. Not just any tattoo, but a lioness. That way we'll have a couple's tattoo of sorts. I'll have the manly lion tattoo and you'll have the feminine and smaller version."
She raised an eyebrow. "Is that the best you got?" Penelope asked, knowing she was a pro at Wii tennis. "Fine. If I win, you have to get Clooney a new puppy to play with. He's getting lonely in his old age."
"Fine," Derek said. "That's fair enough."
They shook on it.
That evening around six, Derek and Penelope were sitting side by side on her couch, trying their best at a round of Wii tennis. They were doing a best of five. "Say goodbye Hot Stuff!" she yelled as she served the ball for the game point. "Mama is about to win!"
But Derek surprised her. With the flick of his wrist, he quickly hit the ball back and she missed. It whizzed right past her and out of bounds before she could move.
Penelope's face drained of color. "No," she cried. "No, no, no! This can't be happening right now! How did you beat me?"
It seemed the tech analyst would be going under the needle and getting inked.
A/N: Don't forget to review!