Male sperm counts decline with age. It takes a man over 45, five times longer to get his partner pregnant. Even older men who have very young wives (<25 years of age) take four times longer to impregnate their partners.
What does masculinity mean today? What does it mean to be a man? There are so many problems with this question. The real point of enquiry - given that gender is a construct! - should be this: who have we allowed to dictate to us what this void we call masculinity is? The answer: idiots.