The subject of loss was all too familiar, and he wasn't particularly fond of it. How many times had he considered the outcome of a life lived at her side? She'd promised him forever, again and again, but logic always rooted its way between what he might want and what was possible, and each and every time it was always the same answer—impossible. Rose wouldn't be able to keep up with him forever, she'd age, her body would eventually give way to the ebb and sway of time and she'd . . . and then he'd be alone, as he always would be, haunted by the too short life they'd shared. He'd thought for a very brief moment that he might be able to weather the consequences, before Davros and the Crucible, when his hearts had thundered in his chest and his feet moved of their own volition upon that broken street in London months earlier.
But life always happened and it always would, now she had a human counterpart to hold her hand and walk her down the slow path to old age, safely. He might not be perfect, might not handle everything in the same way, but he would take care of her, wouldn't he?
If only he believed it.
The Doctor breathed deep, filling his lungs with the heavy, grease scented oxygen in the restaurant. “I'm not going anywhere,” he said on a tired exhale. Honestly, he was such rubbish with emotions. He was right there, sitting across from her, very much real and unmoving. They might be stuck in this strange place together, but they were together for the moment and even if they could leave . . . he didn't think he'd be able to walk away again.