On July 5, I will celebrate my 20th wedding anniversary. Our sex life has improved (quantity and quality) with the years. Early on there were periods when we went months without sex. Sex has always been important to me, but less so to my wife. Like you, I would like to have sex two nights in a row, but it mostly ain't happening. We now have a romp once or twice per week on average.
Milkyway, perhaps you and I should get together and then set up our spouses with each other
My only suggestion: Have a talk with him outside the bedroom. The starting place might be to find out if he has concerns about his sex drive or if he is satisfied.