Gemma makes the admission after Steph reveals that Sam, who she has been dating for a year, is "not right" for her, following her flirtations with Jeremy McConnell in the house.
Speaking in the bedroom in tonight's episode after Steph hints that she will end her relationship, Gemma suggests that model Sam, who has previously appeared on Channel 4's First Dates, "wants to be famous".
After telling Gemma and Danniella Westbrook that she's feeling much better after spending a few hours in Gillian McKeith's toxic clinic, Gemma tells Steph: "Your boyfriend wants to be famous, you're the famous one. F*ck it off."
Danniella advises her to just be herself in the house and Steph says she feels like "a weight has been lifted off" her shoulders.
Gemma's comments come as Sam recently denied speculation that he and Steph may have planned her flirtations in the house to benefit both of their careers.
When a Twitter user suggested this was the case, Sam said: "I find it very disrespectful the fact you think I would set something like that up.. Come on love!!"
Just over a week ago, Steph and Gemma were embroiled in a massive argument when GC told her she was a "disgrace" for kissing Jeremy while having a boyfriend in the outside world.
Gemma told her: "What you are doing is wrong is so wrong on so many levels. You have a fella, Stephanie. Pull it together. I'm trying to help you. You have a boyfriend. I think you're acting like an absolute disgrace snogging Jeremy and making him look a mug."
Elsewhere, Sam has eclipsed former Hollyoaks actress Steph on Twitter with nearly 201,000 followers compared to Steph's 165,000 (as of Wednesday 27 January at 4.30pm).
Try Reveal's digital edition on iPhone & iPad. Subscribe now & never miss an issue!