Here's a little weekend treat! ;)

"Once you've taken the derivatives with respect to x and y, you can arrange these terms here," the Doctor said, pointing to several equations. "To get the potential vorticity – recall that we said f is constant and zeta is this equation," he continued explaining. "Just tidy up a bit and then you get the Potential Vorticity."

He glanced at his watch for possibly the twelfth time during the lesson. Since arriving at the lecture theatre filled with his students wondering where he was, John had been restless, wishing he could have gotten answers from Clara in her office.

Just a minute to go.

"Here's a little exercise for you: derive the Potential Vorticity as before, but with f being a function of y," he said, writing the exercise on the whiteboard.

The students copied down everything written on the whiteboard before the Doctor dismissed them. He too was eager to leave and was the first to walk out of the room, heading towards where Clara's lecture was held.

John could see students pouring out of the lecture room, so he kept his distance until he spotted the Impossible Girl. It was evident from her face that her mind was elsewhere.

"We need to talk," he blurted, surprising her.

Clara shot him a look as some students began staring at them, smiling. No doubt that they heard about the rumours. "Could you do it a bit more discreetly," she hissed.

"Well, I'm not the one who kissed a colleague for no reason," he whispered through gritted teeth.

She shut her eyes and sighed. "Fine, where?"

"Not our offices, obviously and I wouldn't put it past Jack to bug them," he said as they began walking before an idea came to him. "I know where we can go."

"Where exactly?" she inquired, following him.

"The Department of Mechanical Engineering," he replied, grinning. The building is the perfect place for them to talk as everyone in that department is a walking zombie, too busy with their work to care with what goes on around them. "I'm sure we can use the meeting room – nobody uses it."

Clara said nothing as she trusted him. The Doctor had been working at the university far longer than her, so she followed him around campus, taking a few shortcuts along the way to avoid people.

John looked around the hallway before producing his velcro wallet.

"Are you really 12?" she asked, half-convinced that he's a child stuck in an adult's body.

"It's convenient," he retorted and tapped the wallet against the card reader. "And it has RFID protection... I think."

The door opened and he signalled her to get inside. He scouted the empty hallway one more time before stepping in and closing the door securely.

She crossed her arms, leaning against the table as she waited for him to talk, despite having a good idea of why he had dragged her here in the first place.

Clara waited, but all the Doctor did was stand in front of her awkwardly and avoiding eye contact. "Well."

He tilted his head and gazed at her for a second. "Why did you kiss me that night?"

She dropped her arms and felt her cheeks burning. "I… I don't really know," she answered, thinking he was going to berate her at any moment. "I'm sorry and it won't happen again – it was just out of the blue."

He furrowed his brows and this confused Clara. "There had to be a reason why you suddenly decided to snog me."

She felt even more embarrassed now. "Better not get too narcissistic there, grandpa."

"I'm not the one who kissed this grandpa!" he retorted. "I certainly wouldn't want that kiss to be repeated."

"Well, the feeling's mutual," she said, learning a bit closer.

"Says the elf who kissed me."

They glared at each other, having a contest over who would look even more terrifying.

Clara then blinked and growled. "Screw this!" she exclaimed before roughly grabbing the lapels of the Doctor's jacket and snogging him again.

Unlike the previous incident, John's brain didn't completely fry, but he instead kissed her back with equal passion, setting Clara on the table to get a better angle. His large hands gripped the sides of the desk.

She buried her fingers in his bouncy silver curls, savouring the taste of his lips. Eventually, she pulled away first, almost out of breath.

Both stared at each other quietly, and John leaned his forehead against hers, enjoying the close contact.

"For a grandpa, you sure know how to kiss," she teased. She felt as if the horrible tension between them was slowly dissolving.

"I'm not that old," he grumbled, earning a giggle. "You're not so bad yourself for an elf."

Clara smirked. "Now that I think about it, I don't think you said what you meant in Japanese."

"No," he confessed, capturing her lips in a soft and tender kiss. God, he had been wanting to do this for a while now.

"What exactly did you say?" she asked after they pulled away.

"I'm not telling you," he said cheekily before settling next to her on the desk.

"Will more snogging get you to tell me?"

He snorted.

"I just realised that this room is now a snog box."

John rolled his eyes. "Well don't say it like that… it's still a meeting room… that no one uses."

"Except us."

"Alright, fine, technically speaking, it's a snog box."

An awkward silence enveloped the room.

"We should get going," Clara announced, hopping off the table.

The Doctor mimicked her. "So, um… what about…," he flailed his arms around. "I mean, you… we…"

She turned around, realising what he meant. "Oh yeah," she laughed nervously, unsure either of what this meant. She then came up with a plan. "How about this, we take things slow, get to know each other."

"Right," he agreed. "And keep it a secret, since there's no need for the whole university to know just yet, especially Jack."

"Absolutely."

If she really meant they were going to take things slow, he might as well ask her out on a date. "Would you like to have dinner this weekend?"

She smiled. "I would love that."

"But it would have to be at my place," the Doctor added. "People might spot us if we go to high street."

Clara nodded. "Friday?"

"7 PM?"

"It's a date."

The Doctor smiled shyly before he scratched the back of his head. "So we should just act like normal then, in front of everybody else?"

"If you mean normal by bickering and bantering, yes," Clara said.

He frowned. "I don't do banter."

She arched a brow, slightly perplexed. "Yeah, what were we doing just then?"

"I am against bantering."

She laughed, and it was music to his ears. "Look, I really think we should go before someone finds us in here."

"As I said, nobody ever uses this room."

"Maybe one of the cleaners or new students will."

John rolled his eyes. "Fine, go first, because the last thing I want is people being suspicious, especially Jack Harkness."

"Right," she said, standing before him. She hesitated for a moment before she saw the look in his eyes and pecked him on the lips. "Looking forward to whatever we argue next."

The Doctor fought hard not to show his emotions as he merely grunted before she left. After waiting for a few seconds, he grinned from ear to ear.

He felt as if he was on cloud nine, not quite believing he had kissed and been kissed by Clara Oswald.

John waited for a little over ten minutes before deciding to leave the room and return to office. No one would suspect a single thing. Hopefully.

As soon as he stepped into the department, Jack was on to him like a hound.

"And just where have you been?"

"Who do you think you are?" the Doctor retorted. "My father?"

"Your kids' future godfather," Jack replied. "Your and Clara's kid's future godfather."

John sighed, mentally preparing for another interrogation as his best friend followed him into the office. "I went out to get some coffee."

"Your lecture ends at 10, and you've been gone for half an hour."

"Had coffee at Starbucks," the Doctor lied smoothly, looking away from him.

Jack squinted his eyes. "Funny you should mention that because I saw Clara carrying a Starbucks coffee cup."

"So?"

"Were you two having coffee together?" he asked smugly.

They were doing something much better than drinking coffee, but the Doctor wasn't going to say that. Instead, he feigned annoyance and crossed his arms. "I didn't see her there, and even if I did, what were you expecting me to do?"

"Ask her out on a date."

He had done exactly that. "No."

"Go up to her and tell her how you truly feel," Jack advised. "Honesty is the best policy as they say."

"Please stop being nosy."

Jack grinned. "I will once you two get married and have kids, or at least, reduce my pestering frequency when you guys date."

He patted John on the back.

"Play her a song while you're at it because that's one way to a woman's heart."

The Doctor knew what Jack was going to do next. "Don't-"

"I need somebody to heal, somebody to know, somebody to have, somebody to hold," Jack sang as he left. "It's easy to say, but it's never the same, I guess I kinda like the way you help me escape."

"Sing," John grumbled.

Jack then screamed. "Clara, the Doctor's looking for you!"

He rose to his feet immediately. "What are you doing?!" he demanded.

"Yes, Jack?" Clara answered, sticking her head out the door as she didn't quite hear him.

Jack Harkness smiled. After over a year of constant arguments between the two, he was happy to know that things were changing, albeit slowly. "The Doctor would like to say something to you."

She arched a brow and leaned against the door frame. "Yeah, is he forfeiting the bet?"

"Why would I do that when I'm leading?" John grumbled.

"Because you'll lose eventually, Dr Magician."

"Do I need to insult your height again?"

Suddenly, the door between their offices swung open. "Please get a room," Jamie McCrimmon said. "It's like I'm in a romantic-comedy film – the bantering is getting out of hand here – are you two into some sort of fetish or something?"

Jack burst out laughing while John and Clara remained silent, face burning red.

"Just get the shagging over with," Jamie muttered, shaking his head before disappearing back into his office.

"Well, this has been very entertaining," Jack began. "But I'll leave you two alone now."

Once Jack Harkness was out of their sight, John glanced into the break room and saw several people in there.

"I hope you're ready to lose, Dr Oswald."

"I still have plenty of time to catch up," she replied. "And I would love to do nothing more than to beat you."

John fought the urge to smile and at the same time control himself. The last sentence was a bit of a turn on if he was completely honest. There was just something about her bossy attitude that he liked. "There's a bit 'if' floating around," he said before retreating to his office. He wished that the weekend would come sooner.

When the Doctor returned home later in the evening, he found Idris in her usual spot, the bed where she was currently resting, but that wasn't what caught his attention, however as he stepped into the kitchen.

There was a pool of vomit close to the fridge.

That was the third time in a month. He didn't think much regarding the first two incidents since she had a habit of doing that if she had eaten too much.

He rushed to his pet to make sure she was alright and from his observations, she seemed fine. It dawned to him that she had since gained a bit of weight and had been acting moody for the past few weeks.

After cleaning the mess, he took out her cage from underneath the sink and carefully placed her inside. "I'm taking you to the vet."

An hour later, Dr John Smith finally got the answer he suspected.

"She's pregnant and I'm sure she'll give birth soon," the vet confirmed after performing a sonogram. He rubbed Idris' ears. "In perhaps, a week."

There were a number of reasons why the Doctor didn't bother to get his cat spayed. One, she's the only cat in the housing area for years. Two, he had thought the suspected father of the soon-to-be kittens was neutered.

"It's better to get her spayed after she gives birth - reduces the risk."

"Yeah," John agreed, staring at his pet. "You've really surprised me this time."

No doubt that Clara would be surprised too.

And more would surely come.