The reality TV star tweeted a photo of Lydia's usually super-flat stomach, with the words: "Four months! What shall we call it?"
But after messages of congratulations flooded in from fans and friends on Friday night (Dec 28), Lydia was forced to deny she was pregnant.
She tweeted: "OMG I'm not preggers sorry guys just to much Chinese food @tomkilbey you was not suppose to tweet that pic tut tut."
Even their TOWIE co-star Lucy Mecklenburgh seemed to have been taken in, writing the message: "I'm godmother!!!"
Lydia and former Portsmouth FC football player Tom started dating earlier this year and their romance played out in front of the cameras on the ITV2 reality show.
But Lydia announced she was leaving the show during the Christmas special. She told best friend Lucy that she was leaving Essex for a while so she could get away from her ex-boyfriend James 'Arg' Argent.
Do you think Tom was naughty for tweeting that Lydia is pregnant? Tell us below!
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