there's lots of factors in play when you say older man dating a younger woman.
it depends on the age difference between the two, the age bracket these folks are in and of course levels of maturity etc.
there's a huge difference between a 30yo dating a 18yo and a 65yo dating a 53yo. same difference in age, but still very different. once you hit that 50+ age bracket the "rules" shift a bit and age differences aren't viewed the same.
all of this is just me typing my thoughts, of course.