Futanari girls often buy these expensive milking machines because it is the ultimate sex toy. With a suction cup around their well-endowed futanari penis and a powerful motor to pull straight from their well-endowed testicles, a good penis milking machine can make a futanari girl ejaculate for hours, draining her testicles dry and satisfying her libido utterly. As an added bonus, the extracted semen can be sold to perverts online for quite the fortunes.