Ejaculation is the ejecting of semen from the penis , and is usually accompanied by orgasm .

The average size of an erect human penis is between NUMBER@1 -- NUMBER@2 cm -LRB- NUMBER@3 -- NUMBER@4 in -RRB- . The average circumference of a penis is NUMBER@5 cm -LRB- NUMBER@6 in -RRB- when fully erect .
