I was wondering where the ‘blow’ in blow job came from. Moderators, I’m not sure if this is appropriate, so I won’t care if you shut it down. I was just curious.
Because it looks as though one were “blowing” a horn? I have never seen an actual derivation, but it seems as though this term was coined around the beat era, when various jazz genres (many featuring horns) were starting to come into the mainstream.