The British star gets up close and personal with actor Dominic Cooper, 40, in The Escape, which follows Tara, a wife and mother struggling with depression, who falls out of love with husband Mark.
The movie was filmed in the Kent town of Gravesend, which is where Ms Arterton, 32, grew up.
But in a candid interview with Radio Times, she said: “The thing I hate about sex scenes is when they’re pornographic – wide shots with bright lights and naked bodies. But this was all about the faces and it didn’t really matter what we were doing. Dominic and I are very close. It’s like he’s my brother.
“I felt very safe with him. I didn’t feel at all exploited, even though it’s awful to go through and I find it really hard to watch those parts.
“Luckily, because Dominic and I are friends, after doing these prolonged scenes we could switch off afterwards and try to have a laugh.”
Ms Arterton said one of the most difficult parts of shooting the film was working with the two children who play her little son and daughter.
She said: “That was really challenging because usually I’m quite playful around kids. But here I couldn’t do that because it wasn’t my role.
“By the end of the shoot they really hated me. When I came up to them they would run away. It was traumatic for me because I love kids.”
The actress made her film debut in St Trinian’s in 2007 as head girl Kelly.
A year later she was picked out of 1,500 candidates to play Bond girl Strawberry Fields in Quantum Of Solace.