Doctor Foster 'fan theory' spells trouble for Gemma

While viewers cheered over Suranne Jones's Doctor Foster finally getting a bit of respite from her revenge scheme by sleeping with science teacher... but others have suggested there may be more to him than meets the eye.

Fans took to social media this week to theorise that Gemma's new boyfriend James isn't all that he seems, namely that he's a secret spy working with Gemma's evil ex Simon to bring her down.

Simon and Gemma are currently embroiled in a nasty custody battle over their son Tom, and the plot twist that saw Simon unexpectedly show up to a nightclub and take a photograph of a boozy Gemma has led fans to think her new lover may be in on it.

"James (the teacher) is one of Simon's spies," one watcher tweeted. "How else would Simon have known that Gemma was in the club?"

Others have also raised their suspicions in light of James's desire to stick with Gemma despite her poor treatment of him, which included a slightly unenthusiastic post-coital chat.

"Mr Nice Teacher is clearly either a glutton for punishment, or Simon's spy. Or both," tweeted another fan.

That Simon would partner with a mole wouldn't be an enormous surprise based on his past actions, which this week also included asking incredibly intimate questions to his former neighbour Neil, who had an affair with Gemma in the show's first series.

"Did you have fun?" he asked. "Did she strip off at the end of the bed because she likes to take her clothes off in front of you? She's got a good body, right? For her age?"

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