Fun fact 1: a man's semen coagulates (thickens) when it's ejaculated in order to stay in place near the cervix and prevent competitors' semen from reaching it.
Fun fact 2: evolution has shaped the head of the penis however to displace competitors' semen from the vagina. Technically the larger the penis the better.
A reminder that we are animals and that monogamy was definitely not the norm for a very, very long time.
#evolution #monogamy #openrelationship #anatomy #survivalofthefittest