Often, they feature a competitive element, with the winner being the participant able to ejaculate first, last, or farthest depending on the pre-established rules.
After a man learns to ejaculate in the presence of his partner, the couple gets to another stage where the man's hand is replaced with the hand of his partner.
A positive relationship between the amount of ejaculate material received and lifetime reproductive output, as male-transferred material increases female longevity.
When used to treat benign prostatic hyperplasia, more frequent complaints include reduced libido, impotence, reduced ejaculate volume, and within three days, chemical castration.