Less interest in sex. Of this behaviour?

Thank you for your question. There are several reasons . Many times it is down to a lack of knowledge and confidence about sexual matters. As a subject sex and relationships are not taught. Whatever is learnt is often not considered 'good' by cultured families. There may be seVeral beliefs about what a 'good' man or woman should do in sex. The miscommunication is responsible for lot of undiscussed problems. May I suggest that you both read "New male sexuality" by Bernie Zilbergeld. It's available on Amazon. A lot of myths will get cleared. If after 6 months of working through this you find no change it may be worth consulting a sexologist near you for help. Hope this clarifies it somewhat. If your husband is also concerned about his low desire your doctor may recommend some basic tests. General health and fitness are important for a good sexual interest. Other tests may be required if any problem is found on examination. Best wishes