She hated when he lied.
When he'd hesitate and glance away for a second, before plastering a smile on his face and try to reassure her. His soft smiles that were always, inexplicably full of sorrow. And when his eyes gleamed with that certain happiness, she could tell he was reminiscing about her. The one he'd lost. The ghost. She had never been jealous of a dead person before. But here she was, wondering what had made her so special, and why – why was she willingly walking into something she knew would end up badly?
But most of all, she hated when he treated her like a child. A fragile flower, that would break at the slightest touch. Because Clara Oswald was anything but fragile, and not even a thousand year old alien could convince her so.
"Clara?" She heard him yell, "Clara where are you?"
"In my room!" she responded, muttering for god's sake under her breath.
A few minutes passed as the Doctor searched around, and finally made his way to the deep-red couch that served as her bed. He slumped onto the couch, his breathing ragged from running around.
"What wrong with you?" She asked curiously.
"The TARDIS was in a bad mood, she's still shaken up about being called a cow the other day," he replied quickly.
"She locked me in the bathroom, again." She retorted angrily, "As far I see, she had it coming."
"Well, you can't really blame her, she's been feeling off ever since I w-" he stopped himself suddenly.
"Ever since what?" She asked slowly.
"She's just not used to you, that's all." He rambled quickly.
"Doctor?" His eyes pricked up, his face went slightly pink.
"Ever. Since. What?"
He felt the authority in her voice. Part of him wanted to finally give in, and tell her all the secrets he'd been hiding. But secrets kept them safe. He just couldn't. He'd seen the look of confusion and fear on her face when he'd told her by the snarl. And every time he'd remember that face, he winced with pain. He wanted to mean the engine-exploding-traveling-through-a-time-rift thing. But that wasn't the secret he kept closest to his heart.
She doesn't like you, he thought.
She doesn't like the things you feel for her.
He edged closer towards her and cupped her face. And with all his might, he whispered the biggest lie he'd ever told.
"It's nothing."