She's straight, he is bisexual. Can a mixed orientation union work?

"My husband's life is at risk," Jane told me on phone, "he is being threatened and we are not taking it lightly, we need your help."

Well, I am a doctor, not a policeman, I thought to myself. "So it is the wife of this white man who is bringing drama and threatening," Jane explains.

John was an accountant in an NGO and had a lady colleague. The woman was married. She was of Caucasian origin. What began as a friendship between colleagues soon turned into a love affair between John and the white lady and they started having sex. To avoid being caught by their spouses, they introduced each other to their families as colleagues and friends.

"But that is not the cause of my problems doctor," John explains when they visit the sexology clinic.

So it happens that in the process of hiding their relationship the two husbands became friends and drinking partners.

"One day we drunk till late and got a bit out of control, he touched me in the wrong places and alas, one thing led to another. I got carried away…" John confides.

"Just be clear and say that you had sex with another man, in which you were the woman and you have done it repeatedly thereafter until his wife discovered and she now wants to kill you," interjected Jane.

Because of the threat to his life, John had had to resign from his job. The woman continued to threaten and John was worried that anything could happen to him.

"More important for me doctor, I just want you to treat my husband," Jane explained, "I want him to be a man and stop enjoying being a woman with other men," she added.

I could feel the frustration and distress in Jane's voice. I found it important to explain to Jane and John on the complexity of sexual orientation.

First, it is important to understand that up to 20 percent of the population has at one point or another in their life had erotic feelings for the same sex. In many cases, the feelings are not strong enough and not backed by action. Up to 6 percent of men and 4 percent of women, however, identify fully as same sex-oriented. They identify themselves as gays or lesbians.

Due to socialisation, many same-sex oriented individuals maintain heterosexual relationships but have clandestine same-sex relationships. John's case appeared to be in this category. He was bisexual, having sex with both men and women. Some people discover that they are bisexual later in life, sometimes after getting married in heterosexual relationships.

"So what causes this diversity in sexual orientation?" Jane asked.

Unlike popular belief, there is no known one cause to diversity in sexual orientation. Many theories have been advanced to explain it but none is found to exclusively answer. Some theories pin it down to genetics and explain that our sexuality is written in our genes.

Then some explain it using social learning. They explain that it is the way we have been brought up that makes us behave in the way we do sexually.

At one point, some scientists believed that non-heterosexual sex orientation was a psychiatric illness. Repeated studies have however shown that this is not the case and that diverse sexual orientation is not an illness.

It is important to note that religion has greatly influenced the way communities respond to diverse sexual orientations. Many people associate their hostility to diverse sexual orientations to their religious beliefs. Laws that regulate sexual orientation are heavily laden with a religious connotation.

"So how do we help John doctor?" Jane asked anxiously interrupting my lecture on the emotive topic.

"By the way, I don't need help with my sexuality, I just want to be myself, just leave me alone," John interjected, "but you can help me not to be murdered by this woman chasing me all over the place."

This is a case I couldn't help.

I referred John to the police station to seek protection from the potential threat to his life.