A common response to any sentence containing a word with the “er” suffix, to humorously imply that the first speaker was suggesting they should [verb] a hypothetical woman.
Originally this came about in contexts where the word ending in “er” could be truncated to a real verb, such as offering someone a banger (British colloquialism for sausage). “Bang 'er? I hardly know 'er!” Hysterical laughter all around.
In this instance the poster is trying to use “frog” as the verb just so they can make this joke, but one cannot frog a woman.
“Frog 'er? I hardly know 'er!”
A common response to any sentence containing a word with the “er” suffix, to humorously imply that the first speaker was suggesting they should [verb] a hypothetical woman.
Originally this came about in contexts where the word ending in “er” could be truncated to a real verb, such as offering someone a banger (British colloquialism for sausage). “Bang 'er? I hardly know 'er!” Hysterical laughter all around.
In this instance the poster is trying to use “frog” as the verb just so they can make this joke, but one cannot frog a woman.