The inspiration for this little one shot came from a headcanon that lilliesforpotter posted on tumblr and the fact that I was dying to write an AU one shot about James and Lily. It's not particularly long but I had fun writing it so I hope you like it! (Check out lilliesforpotter's blog and I might give you cookies.)

She was finally doing what she'd been studying for for years: this was her first day as a qualified Science teacher and she couldn't have been more excited. She knew that the school day didn't start until nine, but Lily Evans, being the organised person that she was, had arrived dead on quarter past eight that morning and had been sat in the chair behind her desk (after setting up the classroom for the first lesson of the day) for a good twenty minutes reading, when a sharp knock caused her to startle.

"Erm, who is it?" she called.

The door opened and a man around the same age as Lily entered and approached her desk.

"Hi, sorry to bother you." The man held out his hand. "I'm James Potter, teaching Maths up the hall. Just thought I'd come and introduce myself considering we're both new here."

Lily took his hand and smiled. "Nice to meet you James. I'm Lily Evans."

"Oh, I know," he said, sporting a cocky grin.

It was now Lily noticed how untidy James' black hair was, sticking up in all directions at the back, and how impressively tall he seemed up close. Hid glasses had slipped down his nose slightly, which allowed Lily to see how surprisingly bright his hazel eyes were, and how they creased at the side when he grinned.

"How did you know who I was?" Lily chimed as she leant back and crossed her arms, one eyebrow arched.

"Well," he began, perching himself on a desk on the front row, "I always make it my business to know the names of beautiful colleagues."

Lily, despite his smirk, scowled at him before speaking.

"Anyway, who have you got first this morning?"

"Changing the subject are we? Fine, fine," James mumbled after receiving another scathing glare. "Got sixth years first then second years, but after that I've got not a clue. You?"

Lily's mouth fell open. "You don't know who you've got for the rest of the day?"

"I'm not as organised as you since you were clearly set up for first period at around six this morning by the look of this place. I've got my timetable in my desk somewhere anyway, it'll be fine."

Lily had known her timetable for her classes almost a month ago and had been planning lessons long before that, but rolled her eyes at his ease and a small smile played around her lips.

"Who've you got this morning?"

"Third years then fourth years, then sixth years after break." She paused for a moment. "Please don't damage any of my sixth years before they have their first lesson with me, I can already tell you're the troublesome type."

James' eyes sparkled and, what Lily was beginning to think was his signature grin, crept up onto his face.

"You've got me down to a tee."

In one swift movement, James pushed himself off the desk and lowered himself into a slight bow, keeping his eyes locked on Lily's.

"I assume I'll be seeing you soon, in the staff room at lunch if not before."

Lily was about to question when she could possibly see him before lunch when he turned and made his way towards the door.

"See you later, Miss Evans," he called as the door of her classroom shut behind him.

Insufferable, she thought as she say herself down and picked up her book once more.

By break, Lily was happier than she'd been for a long time. She'd had a brilliant first two lessons and the children seemed to have taken to her surprisingly well considering it was her first day. She half expected James to wander in as she couldn't think of another time he could possibly see her before lunch - providing he wasn't stupid enough to visit her during lessons, which she couldn't really put past him - but as the bell went to commence the start of third period, she shook that thought from her mind and sat behind her desk, awaiting the students' arrival.

Within ten minutes, her lesson was in full flow and she was watching her students labour over the experiment they were working on with a satisfied smirk on her face.

A boy with light brown messy hair on the front row raised his hand and Lily made her way over.

"Sorry Miss Evans," he said as she approached. "But I was just wondering how you met Mr Potter."

Lily's eyebrows drew together as the heads of the children around the boy looked up to hear her answer. "Sorry, but I'm not sure what you mean."

"Well," the boy began, "We had Mr Potter first period today, and he said we should look forward to your class as he claimed you're a really good teacher. I was just wondering how you knew each other."

Lily was quite puzzled as to where this boy's (and the rest of the students') interest came from, but answered anyway.

"I see. Well, we actually only met this morning so his claims of my excellent teaching skills, however true they are, were completely without evidence."

"Benjy!" a voice exclaimed from behind her, and Lily whipped round to see James stood at the door.

"I thought I told you that was to stay between us, Mr Lupin?" he said, winking at the brown haired boy who was now laughing into his hand.

"Mr Potter," Lily sighed as James smirked at her. "To what do I owe the pleasure?"

"Well I was wondering if I could borrow a green pen?"

Rolling her eyes, Lily made her way over to her desk and looked up as she said, "What shade? Because I have loads here."

"The colour of your eyes will do."

In an instant the whole classroom was in an uproar of laughter and wolf whistles, so no-one noticed Lily picking up the whiteboard duster until it was flying through the air at James' head. He dodged out the way just in time, but he couldn't stop himself laughing as he watched Lily, scarlet faced, pick up one of the pens from her desk and storm around to meet him at the door.

"Here," she mumbled as she handed him the pen, which to her surprise, he pushed away. He bent down and picked up the duster, handed it to her then grinned.

"I've just remembered I've got one in my bottom drawer, but thanks anyway."

Lily's eyes turned to slits as she whispered, "You're such a git."

"You'll get used to it," he quipped back before he nodded his head at Benjy and left the classroom, the children still laughing in his wake.