"We're both minorities," sums up Madonna, referring to her gender and Everett's homosexuality, "and we both love to shop."

The pair in a scene from The Next Best Thing

The pair, who met 15 years ago through Madonna's ex-husband Sean Penn, co-star in the forthcoming film The Next Best Thing.

Madonna also talks about the difficulty of being a single parent, but admits: "I want another child, but now my whole attitude is, I want to be sure I could envision myself being with this person for a very long time and raising this child together."

The 41-year-old, who is currently dating Lock, Stock and Two Smoking Barrels director Guy Ritchie, 31, conceived her three-year-old daughter Lourdes with ex-boyfriend Carlos Leon.

Madonna also revealed that her daughter has become used to mingling with superstars - but is under the impression that everybody is a celebrity.

"Most people I know are celebrities so she just thinks everyone in the universe is famous."

Celluloid chums

In The Next Best Thing, Madonna, who is a yoga fan, plays a yoga teacher who has a young daughter, while Everett is her charming gay pal.

"There are definite similarities between the characters and us," she admits.

Everett adds: "I don't think the characters are exactly us, but I think there's - certainly from my perspective - a lot of myself accessed in it.

"Like in our friendship - the particular kind of banter we have."

However, Madonna points out that life is not about to imitate art - in the plot her character has a child with her gay friend after a one-night fling.

"I'd have to be in a much more desperate state," she jokes.

Vanity Fair cover by Mario Testino.