Website Den of Geek, leaping upon the fact that Tom is so upset with his mum, has taken a closer look at “the facts” Simon told his son in order to provoke such an emotional reaction.

“It could have something to do with timing,” they point out. “Tom’s age as a 15-year-old was mentioned twice this week, as was the duration of Gemma and Simon’s 15-year marriage and the fact that she hadn’t had a night out like that one in 15 years.

“Marriage and parenthood seem to have happened in very close succession for Gemma and Simon. Did she get pregnant by accident? And did she, initially at least, not want to keep the baby?”

Cruel potential facts for a father to hurl into the face of his son – but it also suggests that, like Harry, Tom was “the product of an unhappy and short-lived relationship”. Only, unlike Sian, Gemma was persuaded into marrying the coercive father of her unborn child.

The tiny detail in Doctor Foster that hints at a major plot twist