Differences in desire

It is fairly common for a man to be more frequently aroused than a woman, but this is not always the case. 

In terms of practical advice, we suggest working both on increasing your arousal and on handling the situation when your desires diverge.

Since interest in physical contact is a combination of psychological and physical factors, you can increase your arousal.  We suggest you begin by increasing the psychological stimuli for desire, i.e. investing in romance. Some examples are: planning a "date" (the planning can also go into a special night at home), music, flowers, chocolate, whatever works for the two of you.  Consider periodically taking turns to surprise each other.  If fatigue has been a factor, take steps to get yourself extra rest when you have a date in mind.  For example, you can try to get a nap in, or you can call on your husband to take a late-night or early-morning shift with household responsibilities in your stead in advance of being together. Physiologically, it takes women longer to become aroused than it takes men.  So give yourselves time for foreplay, intimate physical behavior preceding full marital relations. 

That being said, it is perfectly normal not to desire relations every night.  Perhaps you could discuss with your husband how to communicate with each other when he is interested and you are not without overtones of rejection or pressure.  You can also explore the possibility of less sexual forms of intimacy, such as massage or romance, on such nights.  Developing higher responsiveness to each other when you have different evenings in mind may ultimately enrich your sexual intimacy as well.