Clara is upset about the occurrences in The Witch’s Familiar and Twelve comforts her and they end up sleeping together, which they both feel bad about but don’t regret?

antennapedia: There was a fire on the hearth in the TARDIS library, whether real or not Clara had never bothered to ask. It was irrelevant. It was hot, and she could feel the heat on her back, but it doing nothing. She wrapped her arms around her knees and shivered. Wires in her brain, wires, …