the bump on your dick, call it a ridge or the mushroom shape has been theorized to been come into evolution to scoop out the semen of the previous guy the girl has mated with
a study was conducted to test the hypothesis using artificial vagane and water and starch mix to stimulate semen with same viscosity. with a single thrust of the penis it was found out that the penis almost took out 90 % of the mix from the vagane that was already present
thus lowering chances of the previous mate to fuse his sperm with the egg
this could suggest polyamory relations of women being common back then but that would be wrong. women are coded to choose a single compatible partner by gene
what really suggests is that rape was norm in pre historic societies. a girl could choose any partner and yet u only have to rape her once to pass ur genes. this happens in other animals too. due to rape irrespective of which partner girl chooses baby can always be yours and this sort of cucking was so common that our penis literally evolved to motivate rape more
