flared penis
A flared penis is a penis, usually equine, with a distinctly swollen glans (a flare.) An actual stallion's penis must flare before he can ejaculate, but may visibly flare at any point in his arousal. The biological purpose is to "seal" the glans against the mare's cervix (but not through it) so that ejaculation directly enters into the uterus - the mare's vagina is too hostile for sperm to survive. Flaring is also…