Still, I think I can talk him round, doc. But is he right? Is this really 'a dangerous idea?'

A. Well, this sort of behaviour is quite common among people of a certain age - usually over 35. They get a little bored with their sex lives, and think that introducing someone else into the bedroom would make everything wonderful.

As for your girlfriend, she is probably a little lonely and frustrated, having been divorced for some time. So, no wonder she is really excited at the idea of watching two nice and (I presume) attractive people making out together.

She is obviously a little into what psychologists call 'voyeurism' - which means getting sexual kicks from watching other folks do it. A lot of women - and men - are like that.

And I am sure that she thinks that this little session of 'watching the show' will do no harm.

Indeed, superficially, it all sounds like sexy but harmless fun. However, is that really the case?

I have to tell you that I have seen this same scenario played out a few times in the past. What usually seems to happen is that the 'watcher' eventually gets invited to join in - and agrees. This can have disastrous results.

For instance, I remember a case like yours in which everything went OK for the first three sessions. But after that, the 'third person' got so excited that she took to stimulating herself while watching.

The sight of this had a real erotic effect on the husband, who then started caressing the watching lady's breasts - while he was still having sex with his wife. That led to all sorts of explosions of jealousy, because the wife deeply resented him doing it.

And the eventual result was a certain amount of violence, followed by a divorce.

So what I am saying to you is that you are embarking on a very dangerous path. I really think that you should listen to what your husband says, and tell this lady 'No'.

A. I urge you NOT to try and buy drugs from the Net. Research has shown that a lot of the stuff one can buy in this way is simply fake!

Instead, I think you should go to a doc and discuss what can be done. He may find some correctable cause for your difficulties with potency.

Admittedly, you may need one of the three main erection-producing drugs. But why not discuss with him what would be best for you?

In practice, sildenafil (Viagra) is fine for most guys, and so is vardenafil (Levitra). However, the third drug, which is called tadalafil (Cialis) does have the advantage of a much longer period of action.

This does make life much simpler, because you can take the tablet and know that you will be OK for quite a few hours. So 'timing' is easier.

Q. Good day. I'm female and I am trying to conceive with my partner for four years now, but am unsuccessful. I went to a doc and he just gave me five small tablets. But these did not work. Are there any other tablets that would help make me conceive?

A. I am afraid that it is no good just taking tablets and hoping for the best. What you should do now is to go to a doc who is interested in infertility problems. The doc will examine you carefully, do tests to try and find out exactly what is wrong, and should also fix up a sperm test for your guy.

In the meantime, please try to concentrate your sexual efforts on the day when you are likely to be ovulating (producing an egg). For many women, this is around 14 days before a period is due. Good luck.

A. Viagra (sildenafil) is not licensed for use by women. Much research has been done on its effects in females, but generally, the drug has not been much used.

Admittedly, scientists have found that in some females it produces increased vaginal lubrication. Lubrication is the feminine equivalent of erection.

But, in general, if a woman is having trouble with her sex life, her best course is to see a counsellor who is experienced in sexual matters.

A. No way! Please understand that bleeding between the periods in a woman who is in her 30s or 40s could be due to many things - including cancer of the cervix. So, you must see a doc this week to have a Pap smear, and maybe further tests. I urge you: do not delay.

A. Not at all. But there are also some 'milder' operations, which do not involve removing the whole foreskin. For example, a surgeon-specialist can just make a diamond-shaped cut which 'eases the pressure' on the foreskin, without actually cutting it off. I think you should try and take one of these 'milder' operations.