The Sexual Reference John Lennon and Paul McCartney Dropped Into 'Girl'
By the end of 1965, The Beatles seemed like a completely different band than the one that took America by storm singing “I Want to Hold Your Hand.” Instead of hand-holding, John Lennon was writing songs like “Nowhere Man” and taking trips down memory lane with “In My Life.”
Along with the new subject matter, the band took a wholly new approach to recording their albums. George Harrison had taken up the sitar and debuted it on John’s classic “Norwegian Wood.” Meanwhile, John had all sorts of tricks for “Girl,” another brilliant tune from Rubber Soul.
On that track, John recorded heavy breathing with the assistance of a compressor in the studio. This being the first Beatles album with the band members as “fully fledged potheads,” many take the inhaling sound as a drug reference.
Source: cheatsheet.com