A/N: I haven't read that many who fics so maybe this is not original at all. My apologies if that's the case. Also, first attempt at a Who fic. I am not sure yet I got their "voices" right.

"So where do babies come from?"

The Doctor looked up from the wild mess of wires and gadgets on the console, puzzled. Donna was sitting on the floor, flipping the pages of one of what he had called his stack of "old magazines" but that she had found so fascinating being Vogue editions some 30 years in her future. There were no real spoilers in fashion, were they? Nothing truly life-altering in there, right? No, not really, he had thought.

"What?" - he finally asked.

She didn't look up from the magazine.

"Babies. How do they happen?"

He put down one of the wires he had been holding, not noticing it was the blue one. You can't put the blue one on an active panel on the console cause blue wires tend to get too happy to meet the red wired metal panels. Basic TARDIS tinkering. Of course, basic TARDIS tinkering should also be performed with all eight senses on and no ginger companion asking random questions out of the blue. Oh, the blue. The blue was happy to meet old friend red wired panel. They sparked and sent a happy bolt of electric joy up his hand, to his very happy elbow and further up to his spine where it merrily spread through out his system.

"Your brows are on fire" - Donna mentioned casually, flipping a page.

"I know," he added quickly, patting his eyebrows like it was the most natural thing to expect this time of the year, "all under control now."

"Good. I wouldn't want it to spread up to your hair. With the amount of chemicals you use there we might have ended up learning what Jerry Lewis meant with his Great Balls of Fire. Too young to die on a spaceship, me."

"Very funny, Donna. It would help if you didn't distract me while I'm redistributing the shifting system. This is complicated stuff I'm doing here, we don't want to have our coordinates badly polarized and show up at the wrong planet downwards… or inside out… or something…" He trailed off while he switched switches and clicked clickers checking any possible damages caused by the bolt to the system.

"I was just asking…" she said with the most innocent shrug, resting the magazine on her lap. "I thought you got a high when enlightening us poor clueless humans on the mysteries of Life and the Universe and Everything Else."

The Doctor smiled, still focused on the task at hand. "Ah, good old Doug, he did get the point, he. 42. Ha! That was brilliant."

Donna's turn to look puzzled now.

"You're not making any sense, you know that, don't you? Anyway, Doctor, my question?"

He was busy pumping some green fluid through plastic tubes right into a valve on the console. The TARDIS was making funny slurping sounds. "What?" He asked absent-mindedly "Look at her, sipping all my drink from my funny straw. You're a good old girl" and patted the console with affection.

Donna chuckled lightly. "That'd be so naughty if it wasn't so cute."

The Doctor looked at her, burnt eyebrows up. "What are you reading there, Donna? No futuristic porn in my stack, is it? Cause that, well, there can be real big spoilers there, on porn… really big spoilers actually. Tremendous, life altering…" he took a step closer to peek at the magazine resting on her lap: Vogue's Mother's day special 2040. "Ah, nevermind me. Forget I said anything."

"Porn spoilers!" She was positively interested now. "Really?"

But he was back to his work.

"Oh please, Doctor. Why won't you answer any of my questions? You're being such a spoilsport today."

"This is a spoilers free area." He simply said.

"Ok, forget the porn, but, there can't be spoilers in making babies, now, can they? I know how that works already!"

He dropped the mallet on his right foot. He needed new rules for his companions, he thought. A new shinny book of rules that they'd have to sign as soon as they stepped through those blue doors. First one should read "Designated companion will not endanger the Time Lord's life by asking uncomfortable questions while he is operating heavy artefacts". Absolutely necessary that book.

"Don't I?" Donna asked somewhat surprised at his lack of assertion on the matter. "Will humans change their reproductive habits in the future?!" She was freaking out a little. "Have we been doing it WRONG all this time?"

The Doctor pinched the bridge of his nose. This was ridiculous. He might as well call the tinkering off and hope the TARDIS will behave if left to herself for a while longer. "Of course not, Donna" - he sighed - "human reproduction works just fine as it is. There will be improvements in assisted reproduction but you can't really alter the basics there."

She sighed with relief. Some ideas her mind just wasn't ready to wrap itself around. Boxes bigger on the inside, big red spiders trying to feed her to their children and alien planets with enslaved species she could handle. Sex, on the other hand… no, sex was better left the way she knew it was if she wanted to retain certain levels of sanity.

"So, about the babies…" she started only to be interrupted by a groan from the Doctor and his hand pushing on her shoulder as he used her for leverage while he sat on the floor beside her. "Honestly Donna, you know how babies are made. I am pretty sure your mother must have told you back in the day and I am sure you have had your share of… er… experimenting with the concept on your own".

That earned him a playful slap on the arm. He didn't even flinch, he already knew that'd be coming.

"I know dumbo. I was talking about your babies! I am curious about how your lot…" she realised a tad too late that she wasn't as comfortable as she thought she'd be when approaching the subject. "… you know… curious at alien reproduction habits. Not the 'how to' specifically, mind you, more the general idea… as in… are you like us, I mean, not physically, not that I care about your skinny anatomy, at all, more like does it work like with Earth mammals in general? Or you lay eggs or… I don't know!"

He was enjoying seeing her blush. Quite an unusual sight. He wonder if she would had blushed had she been talking about sex instead of merely reproduction. He suspected she probably wouldn't have.

"We don't lay eggs." He said with a smirk. "That'd be funny. But no, we don't. We are pretty similar to humans in that aspect. There are a few things that work differently, our anatomy not being entirely similar of course, but it's the same idea. Some bit of male genetics joining some bit of female genetics and duplicating inside a safe environment until ready to face external conditions on their own".

Donna looked at him. A blank expression on her face. "You made it sound so absolutely uninteresting that I am surprised your species didn't go extinct eons ago".

A change on his features made her realise what she had just said. His eyes were suddenly so dark and the playful glint she loved to see in them was fading, she had to do something.

"Ok, so now tell me about the process. Time to get into the dirty side of it, it's not fair that you know all about our most private interactions while I can't imagine mighty Time Lords going kinky" she quickly added.

The glint was back. She smiled to him - and to herself.

"Ahhhhlright then" he sighed looking at the ceiling and leaning back, stretching his legs and resting on his elbows, "Time Lord sexuality for dummies…" - And of course, another slap. This time on his stomach. He chuckled and went on. "Our external anatomy is pretty similar. Both male and female bodies. Except for, well, something is very different in our females. Very." He coughed a little.

Donna was looking at him intently, her head went a bit to one side and she made this "Oi?" that reminded the Doctor of a puppy dog.

"Our females don't have breasts. Not like these big breasts you have." And he made a nod towards this very particular part of his companion's anatomy and then a fast gulp and he was back staring at all the interesting things happening in the ceiling. "I don't mean yours in particular," he blurted out in a bit of a high pitch "I mean yours as in human females. I mean, this much bigger than men's."

This was fun. Donna thought. This had been a completely innocent question born out of boredom and all those mother&baby beautiful pictures in the magazine but she liked where it was going. Informative, entertaining and it was making the Doctor really uncomfortable and fun to watch. Yes, Donna knew when she had had a great idea and this was one.

"Your females don't have boobs?" She added partly seeking for confirmation for such an odd concept and partly to martyrize the Doctor.

"Not like yourssssspecies' females." He corrected himself.

"But what about Jenny? She had breasts. They were very obviously there".

The Doctor made a face and Donna felt for him. He was really good at putting things behind and she sometimes forgot. She simply forgot.

"I think the cloning machine was not ready for Time Lord biology. She couldn't regenerate either, could she?…" He looked ahead, flexing his legs so he could wrap his arms around them. "Had Jenny been home she would have caused a sensation. Not one to go unnoticed, I can tell you". He smiled lightly. "I would have liked to see that" He looked back to the woman sitting next to him and decided this was no time for sadness. "Anyway," he continued with his explanation, "our chests are not exactly similar cause males have more muscular tone and females are… well… softer. Bit rounder too." He drifted off for a second. Donna wondered how long had it been since he had last got a glimpse of Time Lady "roundness" and how much he probably missed it. But it was just for a second, then he carried on "No real use for them, you see? We don't nurture our children that way."

"Are little Time Lords born with teeth? Cause that is an idea that would really make me cringe" she shared with a bit of disgust.

"No, no teeth. We feed them like the birds. We regurgitate some of…"

She put her hands up and waved. "Don't go into detail there! I really can do without that part. That's disgusting!"

The Doctor laughed softly. "Well, imagine my surprise when I learned how YOU do it!"

They both looked at each other and laughed at how awkward the whole thing was.

"Funny business reproduction!" She exclaimed. "Ok, go on. Then what happens?"

"Well, male and female do join in sexual intercourse, if that's what your dirty mind is wondering about," he offered, "and sex works basically the same way. Then when conception…"

She interrupted him. "What do you mean 'basically the same way'?"

He stared.

She stared back. Then, "You said 'basically the same way' so that implies there are some significant and so very interesting differences" and she winked. She bloody winked at him.

"I thought you said you were not interested in the actual process but the general idea?" He replied, in a futile attempt to get out of the conversation.

"I've changed my mind." And that was it. No apology, no offer to change the subject. Like it was perfectly standard behaviour to ask anyone about their shagging habits in Donna's world. And maybe it was, he realised. Humans. You study their history, their cultures, their lives, you bring them along to the end of the Universe and still they come up with the most fascinating and simple questions and disarm you in all your 900 years of solid been-there-done-that security.

The Doctor was, for once, lost at words. What did he mean by "basically the same way" anyway? It was just an expression. Wasn't it? Sex was… well… basically the same. Then again, maybe not. Cause, really, when it came to human interactions, he had seen it all. Almost. Humans were not keen to have sexual intercourse when he was around. He never gave it much thought but he was suddenly contemplating the possibility that he might have missed something relevant in his education there. But he had read about it, hadn't he? There were manuals in the library. And there were novels. Lots of them. He was certain there had been films too but he had never found the time in any of his visits to Earth to just sit and watch a movie. It was beginning to dawn on him that all he knew about human sexual relations were which body parts went into which other body parts and how the friction must be pleasurable enough to cause climax and spilling and conception. In comparison to Time Lord sex, those were the basics but there was so much more than that. The tingling and the smells and the feeling of absolute connection of the body and mind and the shared time and space… did humans have any of that, he wondered.

"Quit blushing. Start talking".

The Doctor became aware of Donna's eyes fixed on his. A devious smile on her face.

"Honestly Spaceman, the way you're blushing, alien sex must really be something!" She added. "Go on! Don't be shy with me Doctor. I may not be 900 years old but I've lived some interesting times myself. I can take it."