Is it a fact that Men and Horses never Age as far as Sex is concerned?

My Uncle is 68 years old and surprised all of us by announcing grandly that he was marrying a fashion model 35 years his junior. That was a year back and the product is a daughter now 2 months old. I have been wondering whether the age old adage that horses and men never age is true. There are umpteen cases like this. The great actor Anthony Quinn ( Now no more, bless his soul) had a child when he was 82. He must have been a virile man.

So many other cases have come to the fore. The latest is of Rupert Murdoch who married a Chinese girl Wendy who was 38 years younger to him. She has given Murdoch 2 daughters. The couple are now divorcing. One can’t forget the Playboy owner Hugh Hefner wedding a model just a few months back. The fact is that biologically, man in case he exercises and remains fit has his sex drive intact. Thus we see so many older men women marrying or having a relationship. Vatsyayana the great Hindu writer in his Kamasutra has recommended that older men have a relationship with younger women for a longer and healthier life. This perhaps is the answer to the question