The speed of a male’s sperm may depend on the attractiveness of his sex partner.
Researchers studying the red junglefowl — a species in which feminine attractiveness is clearly marked — found that when males mated with more desirable females, there was more seminal fluid, propelling the sperm to greater speeds.
Scientists believe this is because the male birds fire both their left and right ejaculatory ducts — which will also fire individually — when a female is deemed most mate-worthy. They suspect humans do the same thing subconsciously.(source)
Empty both barrels! LoL! Awesome.

