The former Celebrity Big Brother star was booked to appear at the same club as Sam on Friday night (29 January) and clearly didn't like what she saw.
After their joint PA at PURE bar Bexleyheath in Kent, outspoken Megan took to Twitter to vent.
She told her 211,000 followers: "When you do a Pa and someone's 'ex' boyfriend and there tag team thinks there A listers."
When you do a Pa and someone's 'ex' boyfriend and there tag team thinks there A listers— Megan McKenna (@Megan_Mckenna_) January 30, 2016
While Sam has not responded, plenty of fans have muscled in, with Megan retweeting some of them - seeming to prove the criticism was aimed at Sam.
One fan responded: "I unfollowed him the other day! Defo using Steph to make himself known."
Another said: "OOOOHHHH SHOTS FIRED AT SAM."
One critic said: "He is only in the public eye because of @Stephdavis77. Hes def milkin his 10seconds of fame..He needs his own life now."
However, a fan of Sam responded: "Do you not think he is having a hard enough time as it is, without you embarrassing him?"
Ex On The Beach star Megan was in the CBB house with former Hollyoaks star Stephanie Davis, who was dating Sam when she first went into the house.
However, after forming a very strong bond with Irish model Jeremy McConnell in the house, Stephanie appeared to have second thoughts about her relationship with Sam on the outside. He, meanwhile, 'withdrew his support' for Steph as her flirtation with Jeremy grew.
First Dates star and model Sam has even gained more Twitter followers than his actress girlfriend while she's been in the house as sympathy for him grew.
While Megan and Sam attended the PA, Stephanie and Jeremy were finally parted after three weeks in the house when he became the sixth housemate to be evicted.
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