Always make your boy feel in control.
When offered two choices most children will choose the latter. Always offer two choices, each acceptable, but with the preferred option last.

XXX

Rose had hidden the marvellous little book in her bedside cabinet.

The Doctor was trying to settle Sigma back off to sleep in the adjoining room, allowing Rose to take the book back out and peruse it thoughtfully, trying to gain some ideas. Just some inspiration as to how she was to proceed. It was obvious that the Tardis wanted her to do something with this book. Nobody ever found anything in the Tardis unless the old girl specifically wanted them too. But did the Tardis really mean for her to use psychological techniques on the Doctor, and if she did, then why. Could it be that the Tardis really thought that her inhabitants could do with some change, some positive behaviour modification? Or was the Tardis just bored and wanted something funny to happen. Rose was placing bets on the latter but still, this was strange.

The Doctor wasn't that childish. Not really. Sure he whined and pouted just like Sigma, both shared a major breast fixation, both preferred the naked state of being, both loved to be told, you are sooooo big and they were both into playing games... the Doctor's somewhat different to Sigma's…but…so yeah, turns out the Doctor was really childish. Bu it was an endearing sort of childish wasn't it? A lovable sort of grown up childish? Right?

A heated rumble from the Tardis stated that no, it wasn't adorable. Maybe it had been but parenting is supposed to bring a grown up responsible mentality to most. The Doctor seemed to have bypassed the growing up and actually regressed since his son had been born.

He was taking an awfully long time putting the baby to bed. Sigma had to be asleep by now. He was always sleepy after being fed, and Rose couldn't here any angry bedtime noises. So why wasn't the Doctor back in their room with her yet? What could have possible sidetracked him in their sons room? Deciding to go and investigate the case of the missing husband, Rose tiptoed to the doorway dividing the two rooms. The Tardis had provided the room for their son and had left it bare so they could go through the excitement prior to his birth by decorating it themselves. The Doctor had painted the room orange with red clouds and had splotched seemingly random dollops of glow-in-the-dark paint around that actually provided a detailed account of the constellations visible from Earth when the lights were low.

You could only get to the room through their bedroom and then another small hallway. The idea was that if there were ever any intruders on the Tardis, they would have to go through the Doctor and Rose to get to the little one.

Rose crept down the narrow hallway to the nursery, being careful not to do anything to give away her position. She rounded the corner and saw them. Sigma fast asleep in his cot, The Doctor lying flat on his stomach, face dangerously close to the working train set moving about on the tracks on the floor. He was making faint chuffing noises as he watched the speeding toy make its way toward him, letting out the occasional 'choo choo'! The train rounded a bend in the track and proceeded to clunk against the Doctor's cranium where its motors continued to whir with the fruitless intention of motion. The Doctor took a sharp intake of breath and rubbed his sore head as he lifted himself into a sitting position, knocking the train off of the track and on to its side where its wheels continued their futile action.

"What are you doing?" Rose asked in a slightly amused and considerably exasperated tone.

He whipped around quickly at the sound of her voice, mouth gaping like a shocked fish. "I…er…I…um" He looked at the train, still immobile and emitting light train chugging sounds, as if the toy would give him an answer to Rose's question. "I…well…I wanted to see what would happen if something blocked its motion. Theoretically if motion is halted then there is still that potential for the motion that is being stopped. I wanted to know if the potential energy you're stopping it from using could be transferred to something else, and if it did, what form it would take. You see when I provided a barrier that the train was unable to cross, I had expected the train to just stop, whereby creating a build up of potential energy that could somehow be stored and effectively used for something else. However, I did not calculate for the wheels to keep moving despite staying in the same location, therefore burning the energy without the effect of forward motion, so in actual fact expending the energy as waste." He took a breath, looking at Rose and trying to gauge her response. Admittedly what he had just twittered off to her was complete and total nonsense, but hopefully amidst all the rambling, she may have failed to notice that.

"Ri-ight" she elongated the word and nodded mock dumbly, eyebrows slightly raised. "So, you thought the best way to, provide this barrier, to, halt the forward motion as to, collect the potential energy, was to use the hard solidness, of your, head." She paused to take breath every so often, looking up to the corner of her eyes as she tried to match him in his scientific approach, if not I little teasingly. She grinned at him, tongue between teeth, amused by his utter hopelessness.

"Precisely, glad you understand, I'll…er…just continue with the experiments shall I?" He gave her his largest smile, the one he saved for the most special circumstances or when he was genuinely very pleased with himself.

Sigma chose that exact moment to gave a little whimper in his sleep, the sounds of the grown-ups bantering disturbing him momentarily from his deep slumber.

Now at a hushed whisper, "No Doctor, no more experiments, Sigma needs some proper REM and he can't get that with you in here playing with his toys and generally making mischief."

"Oh but…but…toys, and experiments, and experimenting with toys!"

That's where Rose got a little idea.

Sure the book had said give two options, to which both were acceptable, but considering what she had in mind, he would never choose the first anyway.

"Well Doctor, you could stay here and experiment with Sigma's toys," his face lit up, "you could if you wanted to. Or…you could come back to our room with me and we could do our own experiments with some other toys. Some very, adult, toys."

His mouth was at that rather peculiar gaping stage again. Rose could see the various ideas, the pros and cons for each situation battling it out in his mind.

It doesn't take a genius to realise which choice won!

XXX

Over the next couple of days, a lot of choices were proposed and, well, chosen.

Rose couldn't stand marmalade but the Doctor seemed to dote on it. She hated the fact that since he knew this, he would always eat marmalade on toast for breakfast and give her a big unexpected French kiss having consumed this repast. He did it just to be annoying. He knew his, she knew this, and even Sigma knew this.

So Rose thought she'd give him a choice. She made sure she was the one preparing breakfast the next day and gave him a choice.

"Right Doctor, jam or honey?"

Of course he chose honey, and Rose then had the pleasure of receiving honey flavoured kisses…not bad at all. Of course Rose absolutely hated getting up earlier so she could make the breakfast, but, the idea was, if she repeated the process enough, he would just get used to it and automatically choose honey, therefore ensuring pleasant kisses when he was ready to go back to making his own breakfast. That repeat until well practised idea was another tip from the book. Honestly, that book was fantastic.

Not only that but she had discovered that the giving choices system also worked with any unsavoury choices she seemed to present him with. No matter what happened and what choices she gave him, he always seemed to choose the latter. The trick was, that if she was trying to get them to work together, as in one person does one thing and the other does another thing, to make work be over and done with quicker, if she always gave the job that she least wanted to do as the second option, then it was guaranteed that the Doctor would chose to do it.

Yes, admittedly it was manipulation to some degree…but it was so good.

It literally worked on everything.

"Doctor, would you like to make me a cup of tea or change Sigma's nappy?"

"Doctor you can witter on about quantum mechanics and quantum theory all night, or you can snuggle up to me shut the hell up and let me sleep.

One thing Rose did notice though, was that whenever she tricked him into doing something he really wouldn't have wanted to do, such as changing Sigma's nappy or visiting her mum, or scrubbing the oven, he got this adorable confused look on his face, like he knew something was going on but couldn't quite place what it was. He soon shook his head firmly as to stop thinking too much and unwittingly carried on with a task he didn't really feel like doing.

As such, life was going much more serenely within the Tardis.

And Rose loved it!