It's amazing, really, how often the Doctor lies. Almost as if he can't form a proper sentence without one. Clara often tries to talk him out of lying, but she can honestly admit that she's no better.
And even as Clara throws her arms around the wary alien, so oblivious to the commotion of the outside world, he lies to her. "I'm not a hugger," he'd say, but tentatively wrap his arms around her and hold her close, taking in her scent and warmth.
And even as she's kissing him, he reminds himself to breathe and lies again, "we shouldn't do this", "this can't end well."
And even as she's moaning against his skin, pressing half-moon shapes into his back that he knows will stay for a while, he lies. "You don't love me, you can't love me," and for once, Clara is able to take his lips again and silence the untrue words.
When she's asleep, he can finally tell the truth, run his fingers through her hair and press light kisses to her warm skin. "I love you," he whispers, finally content with himself, never knowing that she was with him, smiling at his words.