A euphemism for high class sexual intercourse with a young, hot woman (6 out of 10 or higher class)
The term is frequently used in the Greenwich, Eltham, Kidbrooke, Shooters Hill, Blackheath and New Cross areas of South-East London by a family called the Ciprianis.
Bobby; I pulled a high class slim beauty last night, went back to her flat and she gave me fish supper!
Sink; All the best to ya Bobby!
Bobby; (Haddock) Supper!
White fish liquidised in a blender has a similar appearance and taste to hot spunk. Anyone performing a blow job and enjoying the resulting eruption would be treated to a Liquid Fish Supper
And dying in yo' bed many years from now, would ya be willing ta trade all da days from dis here day ta dat fo' one chance, just one chance, ta come back here as young men an' tell our enemies dat dey may take our lives but dey will never take our freedom ... YUB NUB!