old enough to be (one's) father

old enough to be (one's) father

Of a man, much older than one, especially by 20 or more years (i.e., around the age of one's actual father). Used especially when referring to a man who is or might be in a romantic or sexual relationship with a younger person (especially to indicate that the speaker thinks such a pairing would be inappropriate). How could you find him attractive—he's old enough to be your father! Everyone raised their eyebrows when they met Mary's new husband, as he's old enough to be Mary's father. But they do seem very happy together.
See also: enough, father, old
Farlex Dictionary of Idioms.

old enough to be someone's father (or mother)

of a much greater age than someone. informal
1997 Nelson DeMille Plum Island He was probably old enough to be their father, but girls paid attention to money, pure and simple.
See also: enough, father, old
Farlex Partner Idioms Dictionary
See also:
  • old enough to be someone's father
  • old enough to be (one's) mother
  • old enough to be mother
  • not (all) that good/bad/well/poor/etc.
  • not all that good, well, etc.
  • one's sunset years
  • sunset years
  • twilight
  • twilight years
  • jockstrapper