He watches them from a distance, a pained smile on his face.
They're smiling and laughing and happy and he's happy for them, ecstatic really, that it all worked out in the end.
He hadn't meant to come here, never would have tried, never would have considered it, never thought it possible. But impossible is a word that he has increasingly come to associate with his life, and so this turn of events doesn't phase him as much as it probably should.
Clara seems to be half worried and half curious at the mixed look of nostalgia and trying-to-forget and he ignores her. She's asking him what's going through his big alien brain, who are they, and he's not answering, and won't answer, even if she goes blue in the face from repeating herself.
Other Him is up on his feet with a ball and a mitt and playing catch with a boy of about seven with sandy blond hair and blue eyes that he knows is Tony Tyler. Apparently baseball is the preferred sport in this universe. She's sitting on a bench not two meters away, bouncing a pair of messy-haired brown-eyed boys on her lap.
He hears Tony ask her when the twins will be old enough to play ball with him, and she replies that, with inheritance of their father's manic energy, it shouldn't be long at all. Other Him throws the ball up in the air in an easy repetitive motion, claiming that Jack and Mike Tyler-Noble will be the stuff of baseball legend.
The Doctor genuinely grins at that, and thinks that maybe they will. They could go down in the record books as ballpark heroes and have their names on a plaque in Copperstown right next to the Babe himself. If he had ever existed in this universe, that is.
He observes them for a moment longer, Clara holding his hand and standing stiffly beside him. He listens as Rose brags about her sons' as of yet undeveloped athletic talents, a bright smile lighting up her face, with that little bit of tongue poking out just it did in his memories.
Finally managing to turn away, he squeezes Clara's hand and takes the first step back towards the TARDIS. The walk back is mostly silent, until they reach the Old Girl sitting on the same street corner she had when he'd first come to Pete's World. Then Clara narrows her eyes at him, trying to determine his mood. He hadn't answered her when she'd asked who they were, so instead she asks, "Were they important?"
His smile is sad and his eyes look old and he can't keep the tear out of the corner of his eye.
"Yes," he says in a choked near-whisper. "They were important."
And with that he snaps his fingers with far less dramatics than is normal for him and the TARDIS door swings open. Clara lets go of his hand and hurries inside rubbing her arms to warm them up, having dressed for Spain in the spring rather than London in the fall. He takes a moment for himself, and then bounds up to the console with all the false joviality that he can muster and sets a course for their own universe.
Back to the strange case of Clara Oswin Oswald.