TenRose "Check Yes Juliet" by We the Kings
"I'm never gonna leave you."
It wasn't snow, because they never got snow. Just rain, and a blonde pounding on the TARDIS door, screaming for the Doctor to let her in. To remember that they'd be together forever.
She could wait. No matter if it took three seconds or a million years she'd wait for the madman in his Converse and trenchcoat. She already was, leaning against a blue box in the rain because all his self-hate and -distrust had made the TARDIS lock her out and she was yelling in that she was right there and god damn his Timelord arrogance because all she'd done was gone out to buy groceries and it wasn't her fault that there might be an angry mob after her but how was she to know that ball bearings as payment were a deadly insult? And the doors broke open at last, and she ran up to him and grabbed his hand. Told him it was all right.
So what if she was just a human, and he was a Timelord? They'd both felt it, the warmth. The connection, even if he said that they could never be together. Even if his doubts and his past weighed on him like a stone. No matter how many times she had to reassure him that they'd be together forever.