My wife regularly uses her vibrator when I’m not around. But, when she does, it seems there is nothing left for me. We have used it together and, when we do, the sex is great, but I desire more sex than she does. I just don’t understand why she doesn’t want me as much as she wants her vibrator. Obviously, she has needs, but so do I. We’re both over 50, make good money, have a good, communicative relationship (except about sex) and love each other. When we try talking about it, she gets very defensive and denies doing it or needing it. Any suggestions? It could be useful to try to discuss with her the technical aspects of her self-pleasuring. Many men feel threatened by a woman’s vibrator use because they assume it is a replacement penis – which is often untrue. Your wife’s vibrator may be used largely to stimulate her clitoris – the female centre of pleasure. If your normal modus operandi is to focus on intercourse without paying enough attention to her clitoris, it would be understandable if she has chosen to provide herself with supplementary pleasure with guaranteed orgasms. Many woman cannot climax through intercourse alone – the clitoris is not sufficiently engaged. If their partner fails to compensate manually or orally, and if they are shy about explaining their needs or self-stimulating during intercourse, many will resort to private masturbation. Then again, how do you know you desire sex more often than she does? She just might want the best of both worlds. 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: see gu.com/letters-terms. Comments on this piece are premoderated to ensure discussion remains on topics raised by the writer. Please be aware there may be a short delay in comments appearing on the site.