Fascinating Fact: The term “blow job” comes from the Victorian times
Linguist think the sexual connotation of “blow job” evolved from “blowoff,” an expression meaning to finish off, to climax, to end. “Blowoff” in this sense is related to “blow off steam,” to put an end to a emotionally frustrating experience. When a prostitute gave a client a blow job she was helping him “blow off” the steam of sexual arousal. In the 1930s, street-walkers offered oral sex with the phrase “I’ll blow you off.” It suggests ‘I’ll cool you down,’ ‘I’ll release your steam.’
Some linguists think the term “blow job” evolved gradually from an eighteenth century European name for a prostitute, “blower” or “blowsy”. A popular name for penis at the time was “whorepipe,” and it is easy to see how the woman who played the instrument came to be called a “blower.”
It was also used to describe jet planes in World War Two and in Ancient Greece, the common slang for a blow job was “playing the flute”.