This story is based off a piece of fan art I saw on deviantART a while back. It amused me so much I had to write this little fic after it.

Enjoy! As always, I don't own Doctor Who.

Rose often wondered if the Doctor ever actually slept. He always was running around with seemingly boundless energy like a child who had too many E-numbers.

It didn't get much better after his regeneration. In fact, his energy levels seemed to increase! So it was real surprise when she heard him let out a jaw-cracking yawn earlier in the console room. He denied it, of course. Time Lords didn't do such things he assured her. Rose just smiled and nodded.

Of course they didn't.

But this one did!

It had been a long couple of days. Another civilisation saved all thanks to the Doctor's quick wit and a lot of running, so they thought they'd just take some down time in the TARDIS library.

His favourite reading chair had long since been replaced with a slightly larger sofa that they would often lounge about on, usually until Rose fell asleep and the Doctor would have to prod her awake and tell her to go to bed. (Humans and their frankly rubbish sleep cycles, he said quite often.)

Except, this night was different. Rose sat with her cup of hot chocolate reading a glossy magazine while the Doctor sat opposite reading an ancient alien science book which he apparently found absolutely hilarious. Usually he'd burst out laughing at random intervals, pointing out flaws and inaccuracies that Rose sometimes found amusing. He pointed out a couple, with slightly more subdued laughter than normal.

As the minutes passed by, Rose realised that he'd been much quieter than usual. In fact, other than his post-regenerative coma she'd never heard him be so quiet. She looked up from her magazine, and saw something she'd never expect to see. The Doctor, head bent towards his chest, mouth hanging open slightly, his glasses sliding down his nose and his book dangling precariously from his limp fingers.

Blimey, he was just so adorable, she thought.

But Time Lords didn't need to sleep like Humans do. Didn't they?

"Doctor?" She asked in slight concern.

The only response she got was his steady breathing, mixed with a slight snore.

She had to bite down hard on her lip to keep from laughing.

She reached over tentatively and removed the book from his hands before it fell onto his toes. It was thick and heavy, and for as fashionable Converses were, they did little to protect your feet from falling objects.

He stirred slightly to find a more comfortable position and fell right back into a deep sleep.

She gingerly removed his glasses before they got crushed beneath the seat cushions.

Rose was about to get up and let him sleep in peace. That is until she saw the marker pen resting on a nearby table. Oh, she was so tempted. But with his 'superior senses' she doubted she could get that close without him waking up. Instead she carefully stood up and grabbed a nearby blanket to drape over him. She unfurled it and accidently knocked over a pile of books on the table next to him that fell with a very loud bang.

He didn't even flinch.

A wicked grin spread across her face as she grabbed the pen.

She drew a little moustache on his upper lip, but she froze when he began to stir and mutter incoherently in his sleep. Then he slumped his head back against the pillow behind him and settled right back down. This action gave her full access to his chin and neck, and she smiled even wider and somehow resisted the urge to burst out laughing.

A goatee was added to compliment his new moustache, and she started to draw a little heart tattoo on the side of his neck.

Oh she was so evil.

But she seemed to find a somewhat ticklish part of his skin and he started to stir even more. Rose quickly tossed the marker pen over her shoulder and scooted back over to her side of the sofa as the Doctor's eyes flung open and he sat up straight shouting:

"…and that's why you should never feed a Sontaran after midnight!"

He blinked in confusion, realising his surroundings and the fact that his book was no longer in his hands. He saw his companion curled up on the sofa across from him. Her magazine was upside down and she didn't seem to notice. She also seemed incapable of looking at him.

"Rose?" He squeaked.

"Yeah?"

"What happened to my book?"

"You were about to drop it on your foot." She replied matter-of-factly.

"Ah."

"You fell asleep."

"No I didn't!" He sounded like a petulant child.

She glanced up from her magazine momentarily. Big mistake. He looked so daft with that moustache, goatee and little heart tattoo! She almost drew blood from her lip she chomped down so hard.

"You were snorin' and everythin'! I'm surprised there wasn't drool."

The Doctor wiped at his mouth with the back of his hand and gaped at the black smudge that was transferred to his hand.

Rose was almost exploding from holding her laughter in.

He was suddenly very suspicious. Even the ambient hum of the TARDIS changed pitch and almost sounded amused.

He sprang up and ran to the mirror that hung above the mantle of the fireplace and his suspicions were confirmed.

Rose finally burst out laughing. His wide-eyed expression was priceless.

"Rose. Marion. Tyler." He ground out as he stared at her reflection in the mirror and he barely contained The Oncoming Storm.

Rose just laughed harder.

He turned slowly to face her properly. He took a couple of steps towards her as he stuffed his hands into his trouser pockets.

Despite the ink scrawled across his face, he started to appear quite menacing and Rose's laughter died off.

"You are so dead." He seethed, and she was genuinely scared. He spoke in a voice she'd only heard directed at those he considered an enemy.

Did she just cross a line? Was he about to throw her off the TARDIS?

He pulled something out of his pocket and Rose took a moment to recognise what the object was.

A black permanent marker.

"Oh, no." She stammered catching the playful glint in his eye.

"Oh, yes!" He grinned evilly, looking a bit like an old timey villain with his twisty moustache. She launched herself off the sofa and into the TARDIS corridors with him hot on her heels, his maniacal laughter echoing through the air.

"Mark my words, Rose Tyler. I will have my revenge!"