When best friends make perfect lovers

It is one of the most hotly debated questions about relationships, famously posed in the film When Harry Met Sally: can men and women be just good friends?

According to the neurotic Sally, played by Meg Ryan, they can, but Billy Crystal's Harry insists that platonic friendships are doomed because physical attraction always interferes. "Men and women can't be friends because the sex part always gets in the way," he says when they first meet.

But a survey shatters Harry's cynicism by suggesting that friends who become lovers can maintain their friendship even if the sexual relationship breaks down.

The website Friends Reunited polled 2,000 people and found that only a third of friendships ended as a result of friends becoming lovers.

More than eight in 10 of those questioned admitted that they were aware of the so-called "Harry met Sally syndrome" and feared that having sex with a friend would ruin the friendship.

However, of those who had close friends of the opposite sex, 56 per cent of women and 65 per cent of men said they had considered taking the friendship to another level. And of the seven in 10 people who did, only a third said sex had destroyed the friendship.

A third said they were still in the relationship and a third had returned to being good friends.

"If one of your closest friends is a member of the opposite sex and available, and you are looking for a partner, then this does seem the obvious place to start," said Rhoda Moore, head of the website's dating division.

"It's just as likely that if it doesn't work out, you'll go back to just being friends. Best-friend dating makes sense because deep friendship is at the core of any longlasting romantic relationship."

Asked why they had not dated a best friend, half of women said it was because they "just didn't fancy him" and a fifth said they feared it would destroy the friendship. Around a third of men and women shied away from romance with a best friend because "we just know each other too well".

Experts remain divided over whether men and women can ever be just good friends. Susan Quilliam, a relationship psychologist, said she believed that friendship was an excellent foundation for a long-lasting relationship.

"Friends have common values and relationships work if they are built on common values," she said. "The problem is that many people get together on the basis of chemical attraction alone.

"Once the sex 'kicks out', they don't have anything left to maintain a friendship."

But Peter Spalton, who runs workshops on dating, said platonic friendships were possible only if both sides did not want to take the relationship further.

"If one person fancies the other, then the friendship is doomed," he said. "Once someone has made a pass, the whole thing becomes difficult and very awkward."