It has been suggested that the unique and unusual shape of the glans in humans has evolved to serve the function of "scooping" any remnant
semen deposited by other rival males out of the deeper part of the
vagina of a female who may have recently copulated, and thereby decreasing the chance of the rival male from impregnating the female.
[5] Other theorists[
who?] suggest that its distinctive shape evolved to heighten the sexual pleasure experienced by the female during vaginal intercourse. In this theory, the glans increases friction and tension at the mouth of the
vagina by its additional girth and the dilating properties of its probe-like shape.