IT IS said that three is a crowd - but a threesome is one of the most sought-after fantasies in the sex department.

According to sex experts many men and women dream of two or more beautiful partners in bed who will bring them to the peak of ecstasy.

Asiphe Ndlela, a psychologist in Illovo, Johannesburg, says threesomes have been the ultimate pleasure and fond memory for many. She says the most common threesome is a man and two women.

The second most common threesome is a woman and two men.

She says there are threesomes consisting of same-sex individuals. Then there are threesomes that include bisexuals.

Some people just want to experience their partner in a physically intimate situation with another person.

Ndlela says that if done correctly, threesomes can provide couples with a creative new way to explore their inner carnal desires.

Columnist and sexologist Logan Levkoff says many men and women fantasise about threesomes, but that is where it ends.

She says some couples are quite capable of handling it but the majority of people can't because emotions get in the way.

So why would people want a threesome?

Levkoff says threesomes are appealing for various reasons.

She says people fantasise about threesomes for a number of reasons, including the opportunity to totally make out with another person without cheating, a chance to share something exciting and breaking a taboo with their partner - or the sensation of an extra pair of hands, eyes, and other things in bed.

She says after six or seven years many couples become bored with monogamous relationships because of the same routine.

"If you're a single person it might be something you've always wanted to do and without the constraints of a relationship you have more freedom.

If you're in a relationship it might be something that comes up because you're comfortable with each other and would like to spice things up a bit," Ndlela says.

"It can be a real turn-on to see someone else enjoying your partner's body and sensual nature. It can even feed the voyeuristic desires of watching and being watched," Ndlela says.

But she warns that threesomes are not a simple business.

"You can't just pop into your car and head off to a threesome willy-nilly. To do things right takes thought and planning," she says.

She advises people to make sure to outline their limitations before dipping their tongue or private bits into unknown waters.

"My advice to anyone going for erotic play is to create boundaries. You and your partner must discuss the dos and don'ts before doing it," Ndlela says.

"You need to communicate what your fantasies are, what you hope to gain and what situations you are comfortable with.

"Threesomes are not like regular sex, they require both imagination and sensitivity. If you plan on having a threesome you need to go into the situation with some idea of what you're going to be doing. You need some threesome rules," Ndlela says.

She cautions that a lot could go wrong if you haven't planned ahead for every potential uncomfortable outcome.

"When a committed couple welcomes another person into their bed the results can be intensely erotic and adventurous or tragically awkward and complicated," Ndlela says.

"Where you end up depends heavily on certain possibilities that should be considered before going ahead with the deed."