This is set after the events of Life as a Circular Paradox
The Doctor winced as he took a tentative step out of the tattoo parlour on Renpar 5. "I cannot believe you actually made me go through with that. It actually glitters and the words are pink. I am the proud owner of a sparkly, pink lettered tattoo. On my bum!"
Grinning, Rose took his hand. "You made me a promise and it's high time you kept it. It's a good thing the tattoos quick healing."
"In my defence, I thought you were dying and I was trying to keep you fighting. I would have promised you anything." He bumped her shoulder with his. "I'm so glad you didn't... die I mean."
"I know. You're rubbish without me." She pulled him to a stop and stood on her tiptoes to kiss him. He wrapped an arm around her waist and pulled her close.
Pulling back a fraction of an inch, the Doctor whispered against Rose's lips. "I love you, and yes, I am completely useless without you. And I must say that if we had to get branded, we couldn't have picked anything that was more factual."
"Well then," Rose caught her tongue between her teeth. "Well then love, I think it's time you prove it."
Removing his arms from around her waist, he grabbed her hand. "Yes, of course, come along Tyler back to the TARDIS." And they ran, laughing the entire way. The Doctor barely paused long enough to close the TARDIS doors as he swept Rose off to their bedroom. She took her time showing the Doctor exactly what his new tattoo meant.
Property of Rose Tyler
He took pleasure in letting her have complete control, at least this once. After all, the words that she had inked underneath the slightly purple TARDIS on her hip were undeniably true.
In charge of the Doctor.