Sex: Ghana's best-kept secret

My mother always says that one of her favourite things about Ghana is the fact that most of the women on TV are fat and middle aged. They have pop stars with names like Mama Mary and Queen Mercy. And when it comes to advertising, they are the face of popular products. Take mosquito coils, for example. As you read this, one brand in particular is flying off the shelves thanks to a TV advert in which two 60-somethings cuddle naked in bed. It's the last thing that I – with my years of exposure to British images of glossified young women – am expecting: a casual, everyday reminder that happily married grandparents are at it as well.

What is so interesting about this is that despite the lack of squeamishness about the fact that adults of all ages, shapes and sizes have sex lives, there is a mysteriousness about sex in Africa. It's just not something people speak about openly, and I was raised on the belief that good Ghanaian women spend all their spare time cooking, bringing up children or – if they really want to let their hair down – dancing in church.

Obviously there is more – there's a reason the average Ghanaian woman conceives four children, for a start. But sex is a more subtle business here, and on the surface it is taboo. Importing porn into Ghana is illegal, for example, and while a lot of Ghanaians complain that the local "Ghallywood" film industry is becoming increasingly pornified, I'm really not convinced there is anything erotic about watching a phenomenally pot-bellied man humping his enthusiastic secretary.

The one thing I have managed to work out is that sex in poor countries generally, Ghana included, can often be a transactional affair. Forget the five "P"s feminist scholars usually associate with sexual politics (power, practices, partners, pleasure and procreation): there are two that apply here – poverty and pecuniary motives.

People use sex to get access to opportunity, and that is openly acknowledged, if only implicitly on the frequent occasions that a ripped young man in Gambia latches on to a middle-aged English woman, or a beautiful young Ghanaian girl agrees to become wife number three or four to a man twice her age.

Polygamous relationships bring their own unique sexual dynamic. Although they are now on the decline, and are already a world away from the mall-crawling youth of West Africa's urban centres. Here the "sleeping schedule" is key – the source of numerous disputes among wives and unlimited headaches for their in-demand husbands. Polygamous men might eat with one wife then sleep with another, or rotate around the women two days at a time. Highly sexed younger wives are known for trying to steal extra nights. But this competition usually seems more about childbearing opportunities, which in turn determine power and resources within the family, than they are about sexual desire.

Sexual desire is what's really interesting here, because it's the one thing that is never discussed. At least that's what I thought until I unearthed the local sex blogosphere. Thanks to Adventures from the Bedrooms of African Women, I'm all the wiser as to the secret motive behind African Dettol douches (not recommended) or that a whole new generation of Africans is willing to embrace the old racist stereotype that African men are "hung like horses".

Nothing in this part of the world is ever as simple as it seems – and sex is no exception. Discussing sex may be taboo, but you can buy sculptures of dildos alongside your Asante stool at the craft shop by the roadside. And when you go to buy your typical painting of people fetching water in the village, don't forget to check out the one beside it of a woman in the throes of orgasm. Although perhaps that's not one for the living room wall.

The Observer,