Ferne is currently in Marbella with her TOWIE co-stars, including boyfriend Charlie Sims, however the Mail Online has exclusively obtained a video which appears to show her getting cosy with a man last month.
Hairdresser Ferne visited Las Vegas with a group of girlfriends and she can be seen in the film with her arms around someone who is not Charlie in a swimming pool.
Ferne has not commented on the footage. Reveal has contacted her rep.
The TOWIE cast touched down in Marbella on Saturday and have begun filming for the new series, which airs later this month.
Earlier this week, Ferne and Charlie were pictured sharing a romantic moment while relaxing in the sun with friends, and also kissing on the beach.
Since then, Charlie declared on Instagram that Ferne is his "soul mate". He added: "Judge us how you like, but love conquers all."
The couple split last year, with cheating accusations being made on both sides, however it was confirmed by Chloe Sims last month that Charlie and Ferne were definitely back on.
For weeks they had teased fans with 'are they/ aren't they' pictures but, on 20 May, Charlie told us at the Reveal Online Fashion Awards that he and Ferne were "very happy" to be back together again.
When he spoke to us, Ferne was out of the country on her girls' holiday in Las Vegas, during which she tweeted about how much she was missing Charlie.
Only time will tell what happens next...