Kerner’s primary thesis is that oral sex (cunnilingus) should not be viewed merely as "foreplay"—an optional precursor to intercourse—but as "coreplay" . He argues that because many women do not consistently reach orgasm through penetration alone, oral stimulation is the most reliable path to female fulfillment.
The audiobook functions as a technical manual, offering step-by-step instructions: ellas llegan primero audiolibro