The film is helmed by director Harald Zwart.
"I promise you that it is super awkward and super unsexy because everyone's staring," femalefirst.co.uk quoted Collins as saying.
Collins, who is rumoured to be dating Bower, also said people are cast together in a film only because they have a certain chemistry.
"We took that chance and...whatever ...It is what it is. People are cast because they have chemistry. You're spending 24 hour days together and it's intense. You have that connection with each other and sometimes that translates to more," she said.
Collins, who was rumoured to have had a fling with actor Taylor Lautner, had previously said it was "inevitable" she would become an actress.
"I started acting when I was two. I think becoming an actress was inevitable as I've always loved dressing up and telling stories, but it was never pushed upon me. I wanted to be a lawyer, ballerina, fashion designer and work at the supermarket. But whatever I wanted to do I was supported," she added.