IT'S an age-old debate, and movies like When Harry Met Sally, My Best Friend's Wedding, Reality Bites and No Strings Attached have all tackled the topic of being merely mates with someone from the opposite sex.
While some may argue that these friendships almost never cross the line, a recent study in Journal of Personality and Social Psychology in the United States estimated that opposite-sex friendships can result in an affair as often as 15 per cent of the time.
In another study of 186 heterosexual college students, 32 per cent of females and 57 per cent of males reported at least moderate levels of attraction to their closest opposite-sex friend.
Kinterlink International Marriage and Therapist Centre director, and US-licensed marriage and family therapist associate Charis Wong believes that although opposite-sex friendships are possible, it should be entered into with caution.
"As the gender gap narrows, it's increasingly common to have platonic relationships. After all, more women are involved with outdoor activities while men have no qualms about including girls in their outings. That's all fine and good when you're single.
"However, when you're married, the situation can get challenging because platonic friendship may have to take a few steps back and your spouse may face some uncertainties and doubts.
"Communication with both your spouse and opposite-sex friend on how the platonic friendship and marriage impact each other, and what adjustments are necessary is not only helpful, but crucial.
"If the friendship steps over the boundaries and evolves into physical or emotional intimacy, the marital relationship gets threatened and the spouse is often left feeling alienated, insecure and betrayed."
Registered and licensed counsellor Cheang Meng Wai believes that in this day and age of social networking, it's unlikely that men and women will not form platonic relationships.
"The scenario was very different 20 years ago because more women stayed at home while men came back from the office to be with the family.
"Today, there are numerous clubs and Internet sites that provide avenues for men and women to mingle on a social level.
"Also, with more women working outside the home, it's naive to assume that there hasn't been an increase in the opportunity to form opposite-sex friendships.
"Scientifically, it's also true that there is bound to be physical attraction, especially for men. It needs to be accepted.
"But that does not mean we should act on those feelings."
Those who enter into close opposite-sex friendships after marriage without setting the necessary boundaries to protect the marriage are playing with fire, Wong added.
"Some spouses make the mistake of building emotionally intimate friendships with members of the opposite sex, many times using the reason or excuse of needing emotional support or a third-party opinion.
"But when you build those type of relationships, you're risking hurting at least one person in that circle, it could either be your spouse, friend or even yourself.
"What's worse is there's a high chance of developing sexual attraction to the friend, especially if discussing marital problems with the friend."
Author of relationship book Act Like A Lady, Think Like A Man Steve Harvey, could not agree more.
"I'm just of the belief that a couple should form a two-handed circle. Outside relationships, what good do they bring to your marriage?"
Cheang added that although opposite-sex friendships can be messy, there are ways to make it less complicated.
"Undoubtedly, these type of friendships are very tricky. However, with the right set of boundaries, there should not be any problem. For instance, parties need to define their relationship by questioning motives and reasons.
"Work and hobby-related friendships can be beneficial because there's a valid reason that ties them together. The common factor can create a safe and clean friendship.
"However, both parties need to agree on boundaries, practise self control and have mutual respect for each other."
The situation gets complicated, he said, when there's no clear purpose in the friendship.
"It gets messy when there are problems in the marriage and there's sharing of marital problems with the friend. To avoid misunderstanding or doubt, it's best to discuss marital issues with someone of the same gender, preferably someone older.
"It's very likely that the friendship will develop into a sexual relationship if there's nothing to tie both parties together.
"But if there's a connecting factor, it will divert from physical attraction to the common factor."
