Maybe they would look at each other and feel some odd yearning, but neither of them would know why. They would want to stop, but they would be embarrassed, and neither would know what to say. They would go their separate ways. Who knew? Maybe that happened every day to people who'd once loved each other.
It is an old cliche to say that the future is in the hands of the young. This is no longer true. The quality of life to be enjoyed or the existence to be survived by our children and future generations is in our hands now.