Definition of be old enough to be someone's father (or mother) in English:

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

phrase

informal
  • Be much older than someone (used to suggest that a romantic or sexual relationship between the people concerned is inappropriate)

    ‘he was furious with her for wasting herself on a man old enough to be her father’
    • ‘As a young doctor he also finds himself falling for the same woman - who happens to be old enough to be his mother.’
    • ‘I was terrified, I was talking to a man old enough to be my father and he wanted me to come visit him.’
    • ‘It was another of John's meaningless sexual encounters, and this one with a woman old enough to be his mother.’
    • ‘I went on a ‘date’ with a man old enough to be my father.’
    • ‘You're darling, but you should be chatting up other 21-year-olds instead of someone who's old enough to be your mother.’
    • ‘I am not jealous, because she's old enough to be his mother.’
    • ‘She married a man old enough to be her father, then took him on a honeymoon too strenuous for his heart.’
    • ‘Cat calmly turned around and looked at the trucker, he was old enough to be her father and big enough to crush her with one fist.’
    • ‘Good looking guys are allowed to ogle, but not ones old enough to be your father.’
    • ‘Only minutes later, she returns with her catch of the day: a man old enough to be her father, if not her father's father.’