A / N MARK I: Written because I just love Doctor and Donna banter.

DISCLAIMER: This is not mine to own.

"Doctor, are you sure you don't have OCD?" Donna questioned, absolutely and positively serious.

A huge clanging noise echoed throughout the TARDIS, along with a rather loud "What?" uttered by the Time Lord who was apparently "fixing" something on the afore-mentioned ship.

Fighting the forest of tubes and wires and an extremely long yo-yo, which had somehow managed to get down there, the Doctor's head popped out amongst the miscellany.

"Why do you say that for? I most certainly do not have Obsessive Compulsive Disorder. I might be organised–" he was cut off by Donna's disbelieving scoff.

"You? Organised? That's almost as bad as saying that my Gramps doesn't like sneaking off to watch the stars!" The Doctor opened his big gob, but before he could get a word in, Donna was off again. "If anyone's organised, it's the TARDIS, Herself. She at least knows where all of the rooms are. Anyway, I wasn't even talking about your apparent 'tidiness', Spaceman. I was talking about your need for Converses. Every kind."

"Oh" was all he had to say on that matter, however, and he quickly ducked back under the wild array of wires, anticipating A Lecture from Donna.

"Fifty pairs of Converses. Fifty. Were two pairs not enough? Obviously not." As she took a second to take in a breath, the Doctor's head bobbed back up again and interrupted her tirade.

"Donna! You can't talk, you have at least seventy pairs of shoes. That's twenty more than me! At least thirty of yours are high-at-the-heel, and yet they are totally inappropriate for running! I should know, given that I've–"

"You've what, Doctor? Wore a pair? Do you secretly have a weird fetish with working on the TARDIS in stilettos, do you? Next I'll be finding women's lingerie around in strange places on the TARDIS, and it won't be mine!"

"Donna!" the Doctor admonished, his cheeks going a slight strawberry colour. "I've never worn women's underwear! Never, not at any time! Well, at least not what I remember." He regretted that last sentence, as soon as it had come out.

"Uh-ha! So you admit it! You could've worn them at any time! I'm willing to bet it was while I wasn't here. . ."

The Doctor's face clouded over for a moment, before clearing up again. "Oh, the things I have done, Donna. . ."

Trying to keep up the care-free front, Donna went to the light-hearted banter again. "Yes, I bet you have. . . Trying to get in some fleshy alien's pants. . ."

"Donna!"