Arabella Melville, 45, is a psychologist, writer and shepherd. Her latest book, 'Light My Fire' (Michael Joseph, pounds 14.99), describes how she revitalised her sex life with Colin Johnson, her partner of 20 years. The couple live on a farm in Wales.

Colin and I used to be promiscuous, but seven years ago we decided to be monogamous. Something I never would have thought possible.

We were concerned about the threat of Aids but also realised that we were damaging our long-term relationship. We were looking to other people for excitement instead of harnessing the power of sex to strengthen our own relationship.

I see sex as the ultimate expression of closeness; without it it is very hard to talk about other problems. But I had lost my desire for Colin because of anger and resentment caused by the overall state of our life together.

I found I could rekindle my desire by imagining, or remembering, a particularly good session in bed - preferably with Colin. Rather than be passive, as our culture encourages women to be, I started to instigate sex - sometimes overtly, sometimes by signals such as preparing our favourite chocolate aphrodisiac pudding in the evening. Colin was delighted]

Once we had established that the success of our sex life was a joint responsibility, things started to improve on all levels. We worked hard at pleasing each other and started to talk openly about our feelings. We're still making progress, but it's incredible how quickly that old gap starts widening if we go for a couple of weeks without having sex.

Running the farm is very demanding and it can be a problem getting to bed at a time when both of us have enough energy for sex. Colin is raring to go at 2 or 3am and gets irritated by the fact that I like to be asleep by midnight. Sometimes I think we're mismatched, but we struggle on.

Colin being a night person does have its advantages. During lambing in April and November, he's the one who stays up through the night to check the ewes at regular intervals while I get my sleep. He wakes me if one them is having trouble. I like to be the one to help them give birth, my hands are so much smaller than his.

I'm very fond of my sheep. They make me feel grounded. I often stroll up into the fields just before I go to bed at night and talk to them. They're all dozy and quiet, not actually asleep but lying down. Sometimes they get up and come and surround me. It's wonderful to be accepted by the flock in this sort of psychic joining and sharing. I find it incredibly relaxing.

I rarely have trouble going off to sleep and take my dreams seriously. I once dreamt that I was in bed with Michael Heseltine, who, unfortunately, had not come prepared for safe sex. In my dreams I've often refused sex with a stranger because neither of us had a condom and I find this reassuring. It shows that my conscious mind can shape my unconscious.

Once I was asked to write an erotic book and was horrified because my sex life at the time was zero. I worked really hard at fantasising a lot about sex in the daytime and, sure enough, had the most wonderful erotic dreams at night, which I then wrote about. It was a full-time job.

Most importantly, dreams are a way of keeping a check on your darker self. My mother is my 'personal prude'. She'll turn up in my dreams at a party and hover, wanting to join in the fun but not being able to. When I have these dreams I realise that, however much I have rejected it at a conscious level, I am still prey to the feeling that I am not really entitled to enjoy myself.

Colin and I never wear anything in bed, even when it's cold outside. I need that feeling of skin on skin. It's nice to sleep curled up together, but we tend to move apart during the night. I don't think sleeping positions necessarily say anything about a relationship. Colin probably moves away because he gets too hot.

I am usually woken at about 8am - not at all early for a shepherd - by the nagging of lambs. I can't stand it that Buttercup's boys are hungry, so it's up and out into the weather feeding animals for an hour before I start on our breakfast.

With luck, Colin will get up, but it depends on his mood. Having breakfast with Colin is an anchor in the day somehow. I don't know where I am if he doesn't come down and it's not worth making porridge for one.

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