I am a 41-year-old woman who has been married for two years. I love my husband and still find him physically attractive, but I do not feel in the mood for sex very often, and never initiate. I even worry about him initiating, as I may not be able to respond in the same way and will make him feel rejected. In my 20s I had a lot of one-night stands after nights out, or with guys I knew and liked, but even then it was about the excitement and seduction rather than the physical sensation. I have only ever managed to have an orgasm by myself. In the past year, when we have sex I get aroused but then lose interest at the moment of penetration. This can be quite abrupt and leave my husband puzzled. I am worried that my lack of sexual desire may become detrimental to our intimacy and relationship. Your central pleasure centre is your clitoris, and your sexual arousal is dependent on it. For many women, connection with clitoral stimulation is lost once penetration starts, and it is replaced by different feelings which are not always pleasant. If you can teach your partner to continue stimulating your clitoris during penetration, you will have far more pleasurable sensations. Some women take matters into their own hands and pleasure themselves during penetration, while others learn by trial and error which coital positions are most likely to stimulate their clitoris. It is understandable that your confusion and disappointment over your sexual response once intercourse starts should cause you to want to withdraw from sex altogether. But you simply have to take more responsibility for your own pleasure and ask for what you need. Pamela Stephenson Connolly is a US-based psychotherapist who specialises in treating sexual disorders. If you would like advice from Pamela on sexual matters, send us a brief description of your concerns to private.lives@theguardian.com (please don’t send attachments). Each week, Pamela chooses one problem to answer, which will be published online. She regrets that she cannot enter into personal correspondence. Submissions are subject to our terms and conditions.