Your pairing choice: "He should not have even been there to begin with..."
He should not have even been there to begin with.
But even with all his years, all his regenerations, all his experiences, there was one fundamental truth:
He could never resist Rose Tyler.
The Doctor knew what the TARDIS was up to as soon as he opened the doors. It had been a frequent stop during his eleventh life, brief moments here and there when Amy was asleep or home with Rory. Never more than ten or so minutes- just a glimpse, a breath of time to remind himself that she was alive, happy. A moment to soothe the ache in his hearts that had existed ever since she left.
It had been years now, though, since his last visit. This new body wasn’t one for sentimentality, no matter how much the ache had grown. His TARDIS landing him here only meant she wanted to meddle, and that was his job, not hers. She still locked him out, though, and only the thought of being picked up by the cops for disturbing the peace stopped him from yelling at her.
Grudgingly, he crossed the street into a very familiar shop.
Two floors up, there she was- beautiful, radiant, still so full of fire and light even though she had yet to realize it. She was talking with a customer- better that way. Even though she had no reason to recognize him, it was still safer-
She caught his eye. Quickly, he turned, and fled.
He should not have been here to begin with.
Because if there was one fundamental truth, it was that when it came to Rose Tyler, he was still a coward.