And scenes between the two stars got heated in more ways than one.
Dangerous Game, due out on June 16, sees Calum play a footballer who gets mixed up with Russian and Algerian gangsters in a spree of robberies and match fixing.
Jess plays his girlfriend in the British heist film – and that means there were sex scenes to film.
Speaking to Daily Star Online, Ex On The Beach babe Jess said: “The whole cast and crew were so professional, it was great to do my first feature film surrounded by such professionalism.
“I was terrified to do any of the sex scenes because it just makes me cringe”
“Calum was great. I was terrified to do any of the sex scenes because it just makes me cringe. He made me really comfortable because before, I was like ‘Oh my god, this is going to be so embarrassing’.”
However, the filming wasn’t exactly sexy, as Jess explained: “There was so much crew there that it was just a routine. It made me laugh, it put me at ease – I’m glad it’s like that.”
And tempers flared in other scenes, with Jess telling us: “There was a part when I was having a big go at Calum, when I got to shout and be a bit more aggressive, I liked doing that.”
While Jess is best known for her modelling career and time on Ex On The Beach, she hoped to be an actress when she was a child and even went to school to train in performing arts.
The 27-year-old told us: “I always loved it. When I was young, I had a difficult upbringing, and it was like my release.
“There was a pub and my mum used to take me. There was a little stage, and I’d get all the kids to do little shows and we’d charge all the people drinking in the pub a pound to watch us.
“Then I went to Italia Conti and I was doing really well, but I had to drop out because my mum went blind. That ended it there for me and I ended up doing reality.
“But I’m so grateful for the chance to return to my roots. I feel my happiest when I’m acting and on a production set, I loved learning all that I can.”
After Dangerous Game – which also stars Darren Day, Lucy Pinder and Alex Reid – Jess will star in a horror movie set in the London tombs.
But could she end up on our TV screens once more?
Jess teased: “I just moved not far away from Hollyoaks because of Denny’s [Solomona, rugby player and Jess’ fiancé] club. I would actually love to go on Hollyoaks. I’ll just wait outside for a job.”