Most Helpful Guy
Most 40-something guys who hit on young women have the maturity of a 20-year-old themselves. These relationships rarely end well for the young woman. They find themselves married with children, then find out that their husband is also an irresponsible child. If I were the father of a young woman dating a middle-aged man, I would be very concerned.
If a younger woman hits on an older man, it may work out if she knows what she's getting, and he should warn her. She will see him through his decline (quick if she's lucky), and then be widowed when she is still relatively young.