After analyzing interviews with 1,656 married American adults ages 57 to 85, researchers found the expected: Those in the first throes of the passion years had sex more frequently than those whose wedded years had piled up, their sexual edginess sandpapered by life.

But then researchers also found the unexpected: While most long-married individuals reported steady declines in sexual activity, those who passed the 50-year wedded mark began to report a slight increase in their sex lives.

And notably, frequency in the sex lives of long-married couples continued to improve. In the study, published last month in The Archives of Sexual Behavior, researchers noted “that an individual married for 50 years will have somewhat less sex than an individual married for 65 years.”