تعریف و معنای "old enough to be {one's} (mother|father)"

What is the origin of the idiom "old enough to be one's mother/father" and when to use it?

This idiom implies that one person is considerably older than the other, to the extent that they could be the other person's parent. This idiom is often used to highlight a substantial age gap between individuals, especially in romantic or relationship contexts. It is typically used in a derogatory or judgmental manner, suggesting that the age difference is notable and may be inappropriate or frowned upon by societal norms. The origin of this idiom is unclear, but it likely emerged from some cultural and social norms. It is important to use this idiom with sensitivity and respect, as it may carry negative connotations and could be considered offensive in some situations.