Fergie didn't realise she was cheating

Fergie didn't realise sleeping with women was cheating until she spoke to her therapist.

The singer has always been open about her bisexuality with her husband Josh Duhamel, but admits she was initially confused about what it meant for their relationship. She only realised how hurtful it would be for her spouse if she fooled around with a women after having counselling.

"I've been very honest with him from the get-go. I think women are beautiful, I've had a lot of fun with women, and I'm not ashamed of it," she told The Advocate magazine. "The problem is that I also love a well-endowed man. But just because I enjoy women doesn't mean I'm allowed to have affairs in my relationship. I learned through talking with my therapist that it is still cheating even if it's with girls, so there is a rule there."

Fergie, 34, insists she has always been honest about her sexuality, claiming it is a part of her she has never tried to hide. "The funny thing is that I was very open about that from the very beginning, and everyone was acting like it was some new trend. Go back four or five years, people, and you'll see the same answer," she said.

She has a fulfilling sex life with Josh, and while they experiment, there are some things they will never do. She explained: "Threesomes? No, that's not happening. We're too smart for that. We've done some filming but with no tape in the camera."

Fergie and Josh's marriage has been under pressure in recent weeks. The pair have been forced to deny claims the actor had an affair with a stripper just months after they married in January.