River Song was not a stupid woman. She had seen the pain, fleetingly before the Doctor controlled his expression, more than once. And she knew it had to do with her.
For a long time she had thought it was because she had killed him, even though he had lived through it by his own machinations. But then she realized... it was fear for her, not fear of her... that caused him to react with agonizing despair. It was almost imperceptible... unless one knew him very well. Which she did. Who could know him better? He did not think like a human being... that was what his Companions and other humans usually failed to understand. They saw the acts, not the motivations. She could see both. He was courageous and irresponsible, sweet and manipulative, loving and arrogant in his superiority. She loved him. But she knew him.
So it took her by surprise when the TARDIS materialized and before the vroop vroop sound had even faded, he had disabled the security cameras and the cell door locks, demanded she get up and come with him, and grabbed her by one wrist, practically dragging her to the big blue box that was in some strange way a second mother to her. He stepped in, still gripping her wrist, and snapped at the TARDIS to take them somewhere - anywhere - away from the Stormcage.
And then he kissed her.
That in and of itself was unusual; generally she instigated any kissing. When it came to that particular enjoyable activity, he was typically diffident, even shy, as though unsure how an advance would be received. But right now he was kissing her fiercely, bruising her lips, and his hands were clenched in her hair, almost hurting her with his desperation. She let out a muffled protesting sound and he let go of her, horrified at himself, refusing to look her in the eye. He muttered something that might have been an apology and turned away.
It made her want to cry.
Why couldn't he see how much he was loved? How much he deserved love? He wasn't perfect, but he wasn't the complete monster he - and the Silence that had raised her - believed he was. He wasn't. He couldn't be. Or she wouldn't love him. "This is not acceptable, Doctor." Her voice was like a steel trap, so cold and so final, and he winced. "I will not allow this. You cannot treat me this way. Look at me!"
He turned, slowly, and looked into her eyes. "I... River, I... I'm so sorry. You're right, I shouldn't have... I hurt you and I shouldn't have kissed you like that, I..." He trailed off as she shook her head.
"Shut up!. You stupid, stupid fool! There is nothing wrong with kissing me, "like that" or in any other way!" She was shouting at him now. " But I will not allow you to keep blowing hot and cold like this! I love you! And you had better damn well get used to hearing it." Her voice broke, "You... you are loved, and you deserve to be loved. Why can't you believe that?"
He took her face in his hands, gently this time, and whispered, "Why can't you? You're as deserving of love as I am, probably more. You... you're very dear to me, River. I know you can't believe it, any more than I can. But I'll try if you will."
She smiled a watery little smile at him. "Cross your hearts?"
He nodded, suiting action to word, and very very gently, wove his hands back into her hair, and brought his mouth to hers. And this kiss... this kiss was sweet and unhurried and gentle, as though they had all the time in the world, and she parted her lips and moaned quietly into his mouth. He let his eyes close as he gave into the sensations that meant kissing River. The taste of sweet and spicy, and the feel of warm and soft, and the sound of moans and sighs. They loved each other through the endless night that was the TARDIS in flight, and when they went back to the Stormcage, they parted secure in the knowledge that they each were loved.
And that they each deserved that love.