Most people don't get to have more than one first date with the same person, but then again most people don't get to have more than one life with the same person.
Most people weren't Time Lords either, much less human-hybrid-metacrisis-created ones.
Technically— if you could be technical about things like this, and it always got a bit a challenging with the wibbly-wobbly timey-wimeyness of Time— this was going to be their third first date.
Rose tells him she doesn't care much about a third first date, as their first two have been perfectly lovely and she rather thinks they are past the dating stage anyway.
Trying to ignore the wildly blissful memories of their past two nights that statement conjures up, the Doctor insists. He is human now, and he wants to do all the things humans do, and that means going on dates.
Rose raises an eyebrow and opens her mouth with a smirk, but the Doctor cuts her off before she gets further than, "Only most humans go on dates before they—"
He silences her the way he is quickly learning is best. Several minutes later he lifts his head and untangles his hands from her hair, taking deep breaths and struggling to remember what he wanted to her to hear in the first place.
A promise, his Rose-saturated brain eventually supplies. A promise that their third first date will be just as wonderful as their other two, and she won't regret it.
Rose gives in with easy grace and another mischievous smile, her hands sliding down his back as she asks, "So does this mean we have to wait until after to—"
And the Doctor has no choice but to silence her again.
That night he takes her to a posh restaurant with candlelight and multiple kinds of forks. They've never been somewhere really nice on a first date before, and though Rose again says she doesn't care the Doctor can tell she is pleased to put on an elegant dress and take his tuxedo-jacketed arm. Dressing up makes it reminiscent of their past adventures, like seventeenth century Cardiff or that time in Rome, but there's an exciting current of newness as he kisses her hand and tells her she is gorgeous.
They sit on opposite sides of a table, hardly touching in the palpable air of this planned date. The Doctor presents a relatively intact bouquet of flowers and a delicate vase from inside a pocket and places them with a flourish in the middle of the table. Rose laughs, the candlelight sparkling in her warm eyes.
The Doctor wants so much for this night to be perfect, to reflect some of the beauty and grace that Rose has always brought to his existence. He has a particular desire in this newly-granted life, with its passionate body and shortened span, to let her know how special she is, and he doesn't think this time eating chips in a crowded shop would be enough.
Halfway through their dinner, an alien-launched device crashes through the building next door. The Doctor leaps to his feet, Rose kicks off her heels and pulls on trainers from her bag, and they clasp hands and run towards the commotion without a second thought.
It's over by midnight, the threat neutralised, the aliens sent away and the damage addressed. Rose and the Doctor walk home, too weary to look for a cab. Rose's dress is torn and dirty, the Doctor's tux is singed and his tie is lost completely. They've joined hands again, and Rose's stomach rumbles loudly in the quiet street.
"We never got to finish our meal," the Doctor realises sadly. "Our first date—"
"Third first date," Rose interjects.
"—and we didn't even get to finish it." There's a hint of indignation in his voice as he adds, "It's hardly a first date if we don't even finish a meal. It's more like a fraction of a date, a tenth or maybe a thirteenth of a date. Point zero seven six nine two three zero seven seven of a date, if you're rounding up—"
He stops talking as Rose stops walking, tugging gently on his hand. "What?" he asks, turning to face her, worried she's upset with the events of the night.
But Rose is grinning her signature grin at him, tongue peeking cheekily out of the corner of her mouth. "I smell chips," she announces.
The Doctor smiles back at her, acquiescing with glee. "So do I," he says.
And so they end up eating chips on their third first date anyway, tucked together in the corner of a booth in a small, crowded shop. Rose happily and sloppily kisses his cheek; the Doctor rubs the sensitive spot on the back of her knee.
To his surprise, it's not only enough for a first date, it's practically perfect.