"Does this mean I have to call you Daddy?" Jack asked, leaning back on the jump seat. "Because I certainly didn't picture this as a way to do that."
"Hmph," the Doctor said from underneath the TARDIS' console. "I'd think that with being immortal, you wouldn't have such an urge to procreate."
Jack shrugged, knowing the Doctor couldn't see him. "It's not about babies, it's about having fun."
"But Jack, it's so much more than just fun!" the Doctor said, pulling himself out from under the TARDIS and bouncing around the room. "It's about sharing parts of yourself, and creating new life! On Gallifrey--"
The Doctor stopped, then sighed, and slumped down on the jump seat next to Jack. Then, as if he was thinking of the children, he began talking. "You see, Jack, when a boy likes a girl, or a boy likes a boy, or a boy likes an inanimate object very very much, he'll want to share himself with her/him/it. So," the Doctor proceeded, taking two socks out of his bigger-on-the-inside pockets and placing them on his hands, "the boy says to this special person or thing, 'I feel we could profit the future of our world by joining our cells together.' And the person would say--"
At this point, the Doctor stopped using the socks to illuminate his story, and let them do a little dance together as he further explained this process. "--or the thing could indicate in some sort of manner, as having been previously agreed upon, since obviously you wouldn't be just walking up to any old inanimate object and offering to create life together--they'd say, 'I find that idea satisfactory.' So then, you go to your head of house, and begin negotiations for joining. And after the contracts had been drawn up, and the genetic testing done, and the announcements had been made, and you had looked into the Eye of Harmony, and you had gone through the ritual ensuring you were capable of producing the--hmmm, what was the term I heard for this? Oh, yes!--capable of producing the baby batter, ta-da! The cells from you and the cells from your person or thing would be combined together, and you would lie back and think of Gallifrey." At this, the Doctor made the sock puppets walk off, trying his best to make them appear like they were walking hand-in-hand.
Jack never knew that sex could stun him into speechlessness. Not that what the Doctor had just described was sex, but still.
"Um, Doctor? Did you just give me the sex talk?"
"Yes, I did!" the Doctor said proudly. He was still engrossed with his socks.
"No, seriously?" The Doctor just beamed up at Jack. "Doctor, you do realize that I had sex for the 94,537th time last night, right?"
The Doctor looked up, his face crestfallen. "Well, that was the way my dad gave me the talk, so I just thought . . ."
Jack sighed, and pulled the socks off the Doctor's hand before patting it. "And it was a very nice talk. But let me tell you a little about sex . . ."
Eight hours and forty-two minutes later
"What? WHAT??? I could do all those things with Rose . . . I mean, with someone?" The Doctor's face was utterly gobsmacked. Truly, no one had ever been as gobsmacked as he was, and this was saying something, considering how much of a gob the Doctor had.
"Yep." Jack nodded, leaning against the TARDIS' console. "Although I will say that many of them are illegal on most planets. Not like that's ever stopped me, but as for you . . ."
"That's what I've got the TARDIS for!" the Doctor said delightedly. "The Vortex is intergalactic waters--anything's legal there." He rubbed his hands together. "Now, where can I get an umbrella, a large vat of banana pudding, and an accordion at this time of the night?"
"Doctor, don't you think you're forgetting something?" Jack asked, amused by seeing what he had created. Knowledge is power, indeed.
The Doctor stared at him for a long moment, then grinned as he got it. "Oh, yes, right! Now let's see, first I pick up Rose, then I snog her senseless, and then I get the edible underwear and the Kama Sutra pop-up book and the Bananas Foster and put them in the room that's got the biggest bed, and, ooo, I really must slip in an 'I love you' to Rose at some point . . ."
Jack just laughed and headed down the corridor, hearing the Doctor's voice exclaim, "Of course! The Zero Room!" as he went into his bedroom.