Have your partner consume the excess semen and breast milk that is produced during pregnancy.
From a biological perspective, feeding the male is equivalent to asking the male to protect the mother and offspring.

A futanari pregnant woman whose seminal sac (milk
tank) is compressed in her uterus and semen and breast milk overflow just by walking. It is a special type of semen breast milk called drip milk, which is high in fat, rich and flavorful.

The weight of the uterus constantly presses and stimulates the prostate gland. The female glans is sensitive to stimulation. From the open urethra, aphrodisiac pheromones are leaking out to encourage males to ejaculate.