A/N: Well hello there! So, this is my first Mentalist fanfic. Scarey, I know. As the summary says, it's just a quick little one-shot involving Jane, Lisbon, and a body-language lesson. Not as dirty as it sounds, I assure you. It's supposed to be fun, not funny, but humour was the only genre close to fitting the bill, so I went with it. Please enjoy, and feedback is always welcome and well recieved, and that includes constructive criticism.

Apologies for any spelling and/or grammar errors, I'm not that brilliant at writing, as you'll no doubt soon discover. Please enjoy!

Disclaimer; No, I don't own the Mentalist. I can't keep the character's in character in a one-shot, no way I could do it for four seasons' worth of episodes.

"So how do you do it?"

Lisbon's voice drifted across the centre console of Jane's Citroen. Cho, Rigsby and Van Pelt had ransomed the company van, leaving Lisbon to travel the three hour drive from Nevada back to Sacramento in Jane's pathetic excuse for a motor vehicle.

"Are you done insulting my car?" Asked a more-than-testy consultant from the driver's seat. As different as Jane seemed, it had slowly become apparent that he loved his cars as much as any other man could. It didn't help that Lisbon had been throwing jibes at the poor vehicle for the last hour.

"I'm done insulting your...car."

"I don't appreciate the sarcasm, but I will take it as an affirmation. What did you ask me?"

"How do you do it? I mean, I know the basics of reading body language, but you take it to a whole new level. How?" Lisbon had, yet again, had to sit back and watch in awe as Jane used his uncanny ability to spot a rat in the dozen suspects they'd had in their last case.

Jane smiled. His foot eased off the accelerator and dropped to the break to pause the car at a red light.

"You're going to have to be more specific." He hummed, signature grin firmly in place. Lisbon scowled, but complied.

"Tell me how you know when people are lying."

"Easy ground." Jane replied. "Everybody has a tell. Everybody. Most people have several. Even those who consider themselves professionals in the act of lying have a tell."

Lisbon rolled her eyes, but encouraged him to continue.

"Make sure you're in an environment you're suspect is comfortable with. It's no use looking for liars when they're nervous to begin with. Nervousness can easily be mistaken for dishonesty."

She mulled over his words for a minute.

"Shifty gaze, rigid, closed body language, sweats, jerky movements." She said. Jane nodded.

"All signs of a poor liar, or an honest person in a state of unease. It's one of the things that makes you're interrogation rooms useless."

Lisbon scoffed at this, but allowed him to continue.

"It's best to know somebody well enough to know their everyday conversational habits, makes it easier to spot changes that might signal a lie. But since that's not possible with every suspect you come across, its lucky there are other methods. Ask useless questions, just quick ones. What colour is your front door? How many pets do you have? What's your bra size?-."

"Jane!" His companion scalded. He muttered a sorry and continued. The traffic light before them shifted from an angry red to a dull amber.

"Sorry. Anyway, little questions. Thing's you know the answer to are always good. Then, look out for their body language." Lisbon cut him off their.

"What body language do I look for?"

"Oh there's lots of stuff." Jane replied, pausing to release the hand brake and move through the now green orb. "Eye contact and eye movement is usually a sure give away." He stopped again.

"Go on..."

"Right. When we're fabricating a work of fiction, like a lie, someone who is normally organised looks up and to the left, from your point of view. This stimulates the part of the brain dealing with imagination."

"What's 'normally organised'?"

"Someone who fits in with the majority. Anyway, someone who is normally organised looks up and to the left when making something visual. Middle and to the left when creating something auditory."

"How do I know if someone is normally organised or not?"

"Go back to your earlier questions. When you asked them what colour their front door was, where do they look? It's not something a person is likely to lie about, so it's a safe bet that if they looked up and to the right while thinking, they were giving you an honest answer as a normally organised person."

Lisbon took a moment or two to absorb the information before speaking.

"Is that why you always ask suspects stupid, and not to mention usually offensive, questions?" Jane gave a sheepish nod and continued.

"Now that you've got that information stored, you can move on to asking relevant questions. Watch their eyes movements, see where they look when they say certain things. It's an easy way to tell if an inexperienced liar is lying."

"That doesn't sound too hard," Lisbon said, "But what about an experienced liar? How do I tell?"

Jane smiled again and chuckled, lifting his eyes from the road to Lisbon for a second. "I'm intrigued by your curiosity." Lisbon slapped his arm half-heartedly and told him to go on.

"Alright. There are dozens of ways to tell if an experienced liar is lying, but it's a lot harder. It usually requires a level of personal knowledge, which is what makes it more difficult. You really do need to know a little about somebody's everyday behaviour to tell if they're lying. But there are some signs to look out for."

"Like what?" Lisbon needlessly interrupted. Jane glanced to her again, and grinned an eye-creasing smile at the glow of eagerness in his companions eyes.

"Too much eye contact. Being unable to pull their eyes away from yours suggests they're experienced in lying, or that they know enough about the signs of lying to know that shifting their gaze is suspicious. Putting an object between themselves and you also suggests they're lying. Then there are those little tells, like a certain hand or foot movement, or touching a specific body part, that suggests they're lying."

Again, Lisbon mulled over the information. It really was remarkable, she thought, that Jane could make something look and sound so effortless, yet so many people lacked the ability to do it.

"What if somebody knows they're tell, and avoids it?"

Jane shook his head.

"No, a tell is a subconscious action, something you do without thought when you lie. Most people don't even know they have one, until somebody else points it out. I bet you don't know yours."

The senior agent scoffed in her seat. "I don't have a tell." She said.

"Yes you do." Jane said in a sing-song voice, smile yet again set in stone.

"No, I don't." Jane's eyes dropped to Lisbon's hands as she spoke.

"You just did it, liar!" He called, pointing at her with a cheeky grin.

"I don't know what you're talking about."

"It's subtle, I'll admit. Difficult to spot."

"What is? Jane!"

The consultant merely laughed merrily at her expense. Lisbon slapped his arm, far less playfully than the last time.

"What is it then?" She asked over Jane's 'ouch' of self pity.

"You twitch your thumb up and down when you lie." He grumbled.

"What? That's nonsense." Lisbon replied. She looked in horror at her traitorous right hand as her thumb tapped gently against her thigh. She cursed sharply under her breath.

"You don't like swearing, either." Jane commented lightly. Lisbon shot him a look of confusion.

"What are you talking about?"

"You blink every time you swear."

"You're an ass."

"See? There you go! That's not even a bad word, Lisbon."

Said agent turned her upper body to face the driver's side of the car, crossed her arms below her chest, and cocked her chin.

"You know what, Jane, I have a gun. Now feels like a good time to remind you."

Jane barked a laugh.

"Defensive. With body language like that, somebody might think you were being serious."

Lisbon turned her gaze out the window, mumbling something about her thumbs remaining perfectly still when she'd made the threat.

After five minutes of silence in the car, a gas station loomed ahead of them. Lisbon gave a back-handed tap to Jane's arm and gestured to the building.

"Can we stop a second? I want to buy some water."

Jane nodded in reply and pulled into the station, parking to the side so as not to block cars coming in to top up their tanks. He unclipped his seatbelt and climbed out the car at the same time as Lisbon, stretching his aching limbs and back. The air was crisper than he'd expected, but the cool was anything but unwelcome after the near-stifling heat inside of the Citroen.

Lisbon returned in minutes, bottle of water in hand, and stood in front of Jane where he leaned against the hood of the car. She eyed him for a moment or two, suspicious, before tipping her head back and taking a few mouthfuls from the cool bottle. Once she'd taken her fill, she lowered the bottle a licked the remaining moisture from her lip with one almost sensual sweep of her tongue.

Jane raised a brow at her, holding his smile effortlessly in place. He pushed off the car's hood, clasped his hands behind his back, and stood directly in front of her. Lisbon looked up and caught his gaze, and in an unconscious act, Jane knew, flicked her hair back over her shoulder, exposing the smooth skin of her neck. She reached a hand up to fiddle with the cross around her neck, nestled dangerously close to the beginning of her low-cut top. Jane chuckled.

"Seductive." He said, voice a little husky. Lisbon widened her eyes and stared, mouth gaping in a helpless attempt to formulate an argument. Finally, words found her.

"That's ridiculous, Jane. I was drinking water. How is that in any way seductive."

"Tipping your head back, and flicking your hair away, drew my attention to your neck. Licking your lips brought my attention there. Playing with your cross drew my eyes to your breasts. You were seducing me."

The words were teasingly accusing, but accusing nonetheless. Lisbon's eyes narrowed on Jane, then relaxed.

Lisbon twisted the lid tight on the water bottle and walked briskly to the passenger side of the car, reaching for the handle and speaking thus;

"Jane, not in a million years would I ever make an attempt to seduce you. Ever."

And for the second time that day, Lisbon's gaze dropped to her traitorous right hand, thumb tapping lightly against the door handle of the Citroen.

A/N: There we go! I hope you all got my attempt at subtlety at the end there, if not, it doesn't really matter.

Hope everyone enjoyed it

Reviews make my day, so please feel free to drop me one after reading!

Much love, Someone x