Scarlett Johansson finds cheating "awful"

Scarlett Johansson has revealed that she would never consider being in an open relationship.

The actress said that she would never dream of cheating on her fiancé Ryan Reynolds, even though she realises sticking to one partner can be "hard work".

"I believe in finding a soul mate. I've always been in monogamous relationships," Johansson told America's Cosmopolitan magazine. "I would never want to be in an open one. It would be too awful.

"But I don't think monogamy is a natural instinct for human beings. Monogamy can be hard work for some people. I don't think it applies to everybody, and I don't think a lot of people can do it.

"You don't always meet the right person at the right time. It's important for people to figure out their own lives before involving someone else - to gauge where you are and work on your own issues."

Scarlett recently claimed that she was in regular email contact with US presidential candidate Barack Obama. He later denied this.