I used to answer, “Nothing you would understand”. THAT was a tactical error. Very soon after I transitioned to,, “Nothing you would be interested in”. That has worked now for more than 31 years.
that is not true in my case and probably the case of the 12 or 14 other long married couples we know. the ones I see breaking up now are the diverse ones who earned the right to be married some 15 years ago and are now not happy.
Good thing Ron Jeremy isn’t there.