「Flow at the final stage」needs no further explanation for most folks, in particular not for young males who continue to masturbate after ejaculation using their own semen as an added lubricant. Although, note the right element also possibly is an「array of woodies」that suggests a group effort, but not necessarily so:「scrubbing rubbing actions on rod array」or「juices flowing with array of emissions」and so on. Also describes the later stages of a gonorrhea during which a ceaseless flow of pus, blood, and other nasty and stinky schmutz is exuded from the penis tip.
　Or: Not to be outdone by the young males, during ovulation of a female human and estrus of other animals, an individual can become more sexually aroused than at any other time. Adding a dildo and/or an actual penis with enthusiastic action acts just like a kitchen whisk with frothy white discharges whipped up and resembling egg white meringue, mousse, cotton tufts and tassels, or sheep wool:「As a woman's cycle progresses, the mucus secreted from the cervix will change due to hormonal fluctuations. A woman is considered to be ovulating and fertile when the mucus is clear, stretchy and slippery, and looks like egg whites.」
　http://ic.steadyhealth.com/most-fertile-cervical-mucus
　「Understandably this 'foaming at the mouth' phenomenon has your nerves on edge. But, if you were recently tested for sexually transmitted infections (STIs) and received a clean bill-of-health, most likely the foam-like substance is just a result of the combination of two art forms: The Joy of Sex and The Joy of Cooking. The main ingredient here would be semen…. Semen is loaded with protein, a pinch of sugar, and a dash of salt. The dildo and your boyfriend's enthusiastic 'mixing' inside of you acted just like a kitchen whisk.」
　https://goaskalice.columbia.edu/answered-questions/foaming-after-sex

Modern definitions (that generally disregard history) …excluding politically incorrect concepts and other meanings deemed offensive today; may list only pigeonholed definitions, euphemisms, or meaningless mnemonics)
Chinese: foam; suds
Japanese: bubble, foam, froth, head on beer
Unihan extended: froth, foam, bubbles, suds
EDRDG: splash; suds