Winstone, 23, who is currently dating Equus actor Alfie Allen, said that she is more "relaxed" on camera with females.
She told Zoo: "I prefer sex scenes with women. They're a lot more relaxed and a lot more fun."
Winstone's new role in BBC Three's Phoo Action sees her kiss former Hollyoaks actress Gemma Atkinson and US star Heather Graham.
She commented: "I play a lesbian and Gemma is one of my conquests."
> Click here for Tube Talk's preview of Phoo Action