For Ambrose, sex is a methaphor for language.  "Sex, in fact, is the ‘‘whole point . . . Of the entire funhouse!’’ Everywhere Ambrose hears the sound of sex, ‘‘The shluppish whisper, continuous as seawash round the globe, tidelike falls and rises with the circuit of dawn and dusk.’’ He imagines if he had ‘‘X-ray eyes’’ he would see that ‘‘all that normally showed, like restaurants and dance halls and clothing and test-your strength machines was merely preparation and intermission.’’

Romance is just another way of entering the "funhouse."  It has very little to do with the reality of base instincts.