Just as there are no rules for the length of hair relating to age for women, there is none for men either. Stay true to yourself, to your lifestyle and your hair. If you are lucky enough to have such an abundance of hair
and even with a natural curl, flaunt it and don't cut it. His silky curls are already seasoned with some silver highlights on his natural brown base color, just as there are silvery patches lightning up his rugged stubbles.
The key for this look to work is to keep it well groomed and shiny.