After the ball. [Leto]
She knew it was him. It didn't take a genius to figure that much out. Leto may have been covered in head to toe like a desert nomad from an alien world, but Oswin knew it was him all the same. He had been kind, generous with his laughter. She would have deduced that much even if he had not asked her to dance.
And the dance had been ridiculous and wonderful. Mostly it had involved spinning in circles, which unless you took dance lessons from Titanic wasn't much of a dance. But it was best Oswin could do. Leto had done everything that he could. Then, like Cinderella and every damaged damsel before her, Oswin left.
Only this time Oswin didn't wait for royalty to track her down. He had already approached her, made the first move, signaled that things were okay or that he wanted things to be okay. It was Oswin's turn to accept his offer.
The dalek drifted silently to his apartment door. She couldn't knock to announce herself. Instead she gently nudged the body of her craft against the door to announce herself. She was afraid, for him mostly, and for the first time she entertained doubt that the costumed man had been him at all. It occurred to Oswin that she cared for Leto.
That frightened her, too.
Without realizing it, all the electronics in Leto's apartment with speakers began to broadcast an Italian opera.