Are you thinking of Capillaria by Frigyes Karinthy?
Capillaria (Hungarian: Capillária, 1921) is a fantasy novel by Hungarian author Frigyes Karinthy, which depicts an undersea world inhabited exclusively by women, recounts, in a satirical vein reminiscent of the style of Jonathan Swift, the first time that men and women experience sex with one another.
Expressing a pessimistic view of women, the novel suggests that, with disastrous effect, women, who are emotional and illogical, dominate men, the creative, rational force within humanity, who represent the builders of civilization.
The males, known as bullpops, are of small stature. They spend their time building and rebuilding tall, complex, rather phallic towers that the gigantic women destroy as quickly as these structures are erected. Meanwhile, the females engage in sexual adventures, surviving by eating the brains of the miniature men, who have become little more than personified male genitals.
A readily available summary of the relatively rare novel's plot is provided in The Dictionary of Imaginary Places.
The book was a sequel to the author's earlier work, Voyage to Faremido: Gulliver's Fifth Voyage (Utazás Faremidóba; Gulliver ötödik útja) as per the accepted answer to Which Sci-Fi work introduced the concept of an artificial, independent plurality?.
Found by searching for bullpops. The full text is available online, but in Hungarian.