Lyric discussion by gement 

This song's been mostly scrubbed down, but one important lyrics correction left:

We bit our tongues / Sucked our lips into our lungs / Because we were falling is actually We bit our tongues / Sucked our lips into our lungs / 'Til we were falling

(It's definitely not "because," nor "and," no matter how I try to hear the syllable that way.)

To be really direct here, performing oral sex on a man usually involves covering your lips with your teeth, and doing it in an enthusiastic fashion (as a professional must) can cut off your air long enough that you get dizzy. This lyric is both a poetic description and an accurate one.

Biting one's tongue is not usually part of the process, but that seems more figurative to me, as in swallowing one's pride before doing something demeaning. [I do not consider either oral sex or even professional sex to be necessarily demeaning, but the people in this song are not in a good situation.]

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