"I'm just - well enough at ease with the physical act. Sufficiently practised for purpose. Less comfortable with navigating the social interaction around it," Moriarty says, rubbing his chin. "Unless that social interaction involves not asking too many questions beforehand and leaving immediately afterwards."

He peers at her. "Um, yes. Or attachment, might be a better word. I'm unaccustomed to having any kind of particular affection for my, er, partners."