"I don't want to go."

Tears streamed down the Doctor's face as he succumbed to his regeneration energy and…

Zap!

Suddenly, a new man was standing in his place.

"Legs! I've still got legs. Good, arms, fingers (oh, lots of fingers), ears, yes, eyes: two, nose… I've had worse, chin - blimey! Hair… I'm a girl! No, no, I'm not a girl. And there's something else, something… Important. I'm crashing! Geronimo!"

The Doctor stumbled about, trying to gain control of both his new limbs and his space-and-time machine. A dinging went off in the background of the din, and the TARDIS came to a shuddering halt, vibrating slightly as she tried to figure out how to change to fit with her companion.

"Ah, that's better, thanks a lot, you sexy thing!" The Doctor looked down at the ground. "Have I really gotten shorter?"

The TARDIS hummed her assent.

"Well, that's rubbish, I didn't want to be shorter." He sighed and began to walk back towards his bedroom. He soon realized that his legs were jutting out awkwardly as he walked, although it was completely unintentional.

"What…?" the Doctor asked aloud and tried to press his legs back towards each other. "Ouch!" The issue was quite obvious, now that he was paying attention. His previous regeneration's tight trousers were now much too loose everywhere except for one place.

"How the bloody hell did I ever think I was a girl?" the Doctor laughed aloud. He ran to his room to get a better look. His manhood, although not the slightest bit erect, was creating a bulge that could have been an apple stuffed into his pants. Hurriedly pushing his trousers down his legs, his light blue pants came into view. The helpful flap at the front was now simply a window as the Doctor's cock strained against it, trying to hang down more comfortably. And boy, what a view!

The Doctor pushed down the final article of clothing and watched as his behemoth of a dick fell against his leg. At least eight inches long on its own, with beautiful, creamy skin and a pinkish head, it swayed slightly from the aftermath of its imprisonment. His balls matched it perfectly, hanging in just the right spot, heavy and round.

Examining it with awe, the Doctor decided that it was now his right - no, his duty - to test drive his new organ. Oh yeah, and check his reproductive abilities and whatever. But mostly see his cock in action.

The Doctor's hearts began to beat a little bit quicker as he reached towards his dick. It twitched in response, sending jolts of excitement through his body even before he had made full contact. Finally, the Doctor had a firm grip and closed his eyes, picturing sex in all its greatest forms.

He thought of Rose, breasts jiggling as she walked around the TARDIS dressed in nothing more than a skimpy tank top and sweatpants, nipples poking through her top, and how he "accidentally" jabbed her with his erection on more than a few occasions.

The Doctor was fully hard an taking long strokes along his length, pulse racing and heat following the shivers erupting through his body.

He thought of Martha, how she bent over with her tiny thongs, wet pussy lips evading her of any privacy her skimpy pants would have given.

Grabbing his dick with two hands, he pumped and thrust through the slick channel he made, multiple niches sticking out from both ends as he did so.

He thought of Donna, her huge boobs protruding out of every top she owned, and how, since she was so uninterested in a relationship, he was able to go over the top with her, dancing provocatively in bars and giving each other nude massages as he pretended not to notice her staring.

Suddenly, the Doctor felt his orgasm nearly upon him. Wrenching his eyes open, he watched his brand-new fist pumping his brand-new cock, nearly ten inches long now. Balls tightening, he spilled his creamy seed all over the mirror, splattering it and preventing any way of seeing his own face.

Sighing with relief, the Doctor looked down at himself, with his softening cock demasting slowly, and realized that he wasn't sexually tired yet. His large balls were telling him that they were up for another run if he was!

And boy, was he.