Q Doctor, I am a married woman from Manchester, and I am ashamed to admit that earlier this year I foolishly had an affair with a handsome, much younger man.

It was wonderful at the time, but now I regret it. My husband does not know that it happened, so please do not print my name, or any clues to my identity.

The young man has 'dumped' me now and gone off with a girl of his own age. No surprise there!

But I am fretting because I am worried that I could possibly have picked up the HIV/AIDS virus from him? My friends say that a woman cannot get it from ordinary sexual intercourse. So they have told me that I must be OK.

A Well, unfortunately that is not true. Many people have the idea that the HIV, which causes AIDS, cannot be transmitted by straight vaginal intercourse. They think that you can only get HIV through anal sex, or by injecting drugs which have been contaminated with the virus. A few women even believe that it is only men who can get AIDS.

I have to say that these theories are quite wrong. Men and women can and do catch HIV from heterosexual sex. This is becoming commoner worldwide. Not long ago I saw a female patient who has HIV and who told me that she had only ever had vaginal sex.

Incidentally, she was real healthy-looking, and you would never have guessed that there was anything wrong with her.

I have to admit that doctors are a little dependent on patients telling them the truth about how they acquired HIV. What I mean is that it would be possible for a person to catch the virus through being on the 'receiving end' of anal sex, but pretend that they got it as a result of 'straight' sexual intercourse.

That does not strike me as very likely. However, I have noticed that there is one country where an extraordinarily high proportion of HIV-positive men claim to have acquired the infection through using injected drugs. It is possible that these men are so embarrassed about having had 'gay' sex that they are pretending to have been drug-users.

Be that as it may, all medical authorities throughout the world are agreed on one thing: women can catch HIV from sex between a man and a woman using only penis and vagina.

No, don't misunderstand me! I am not saying that every married woman who, like yourself, has a 'fling' with a young man will necessarily get this deadly virus. And I am certainly not saying that you have it.

The odds that you are OK must be very much in your favour. Nevertheless, because of the fact that we know that HIV is prevalent, I would strongly suggest you that you should now go to a doctor for a discreet check-up, including a blood test for the virus.

And I am offering the same advice to any woman, or man, who has had an unwise sexual encounter in recent years. It is better to check these things out than remain ignorant.

Q I am a man of 38, and last week when I persuaded a young woman to come to bed with me, I suddenly found I could not 'manage it', Doctor.

I have had quite a lot to drink. Would that be anything to do with it? Or am I starting to lose my nature?

A No, I am pretty sure you are not losing your nature. However, you are likely to be not far off the truth with your idea that the problem may have been due to alcohol.

Men do tend to forget that although strong drink makes them 'horny', it also makes it more difficult to reach an erection. After a lot of alcohol, almost any man will find it impossible to make love.

However, there may have been other issues here. For example:

1. Were you anxious about having sex with this younger woman?

2. Were you feeling guilty?

3. Were you fretting that you might catch something?

4. Were you on any pills that might have caused temporary impotence?

5. Have you any symptoms that might suggest you are getting 'sugar', like excessive thirst or having to keep passing urine?

6. Do you smoke a lot? Tobacco products damage the tubes that carry blood to the penis.

In summary, my best guess is that this was just a temporary 'failure'. But if it happens again, please see a doctor.

Q I am woman, age 32, and I have suddenly started having those 'multiple orgasms', Doctor.

I think this must be due to the fact that I love my new guy so much. But will they do my health any harm?

A No, multiple orgasms cannot possible harm a woman's health, though they may make her a little tired if she does them regularly.

In fact, many women over the age of 30 find that they have become adept at having multiple orgasms for the first time. Very often, this is because they have linked up with a partner with whom they feel real comfortable, or someone whom they really love. Also, it helps if the guy is good at love play, and understands how to stimulate the female body, especially the clitoris.

I wish both of you well.

Q I have three girlfriends in various parts of the island. Do you think what I am doing is safe?

A No, I do not. Having three lady friends must treble your risk of getting various kinds of sexually transmitted infection, including chlamydia and gonorrhoea.

Just imagine what would happen if one of these women decided to have sex with another guy, and he has an infection! She would give it to you, and you would probably give it to the two other ladies.

Also, this fairly promiscuous life probably trebles the risk of unwanted pregnancy, unless your partners are using safe birth control.