Couples such as yourselves, who have been together for many years, often feel more reluctance than new couples to ask for help because they think, "Hey, we should have this all figured out by now." Bravo to you for being married for 40 years and still recognising that you need advice.
Desire discrepancy between partners is common. You may feel very close, but you are separate people and from time to time those differing thoughts and desires will show. It is not a reflection of how much you love one another or how committed you are to the relationship. A difference in desire is simply a reflection of each individual – their own thoughts, stresses, fitness, age, hormonal balance, energy levels and values.
As a couple, you need to decide whether you will be happy in a companionable relationship or whether you would like to invest in reigniting your sex life, if only to a point where it is sporadic again.
If not, express yourself sexually by yourself, rather than suppressing your sexual drive altogether. After all, those who engage in a regular sex life have fewer heart attacks, fewer strokes, higher immunity and a greater degree of overall health. (body&soul)