As a mother of a son 25 and one 22 I would be very upset if a woman that much older was dating one of my sons.

You have to also consider they haven't had children of their own and will probably want some one day even if they say they don't now. A 40 something woman can't give that to them.

On the flip side of that situation, I've known two women in their 40's and 50's who have married much younger men and have regretted it. Their boy toys took them for all they had and flew the coop.