It's a high five that only men can do. Except instead of slapping hands together you slap penises together.

An epic slapping together of hands by brofriends. Doesn't involve any other body parts, JUST HANDS! A guy five should hurt the palm of your hand, otherwise you aren't doing it right. Your hand should tingle for hours afterwards.

A guy five is done when something epic has happened, or when the excitement of life and brofriendship gets to be too much. Often coupled with a brohug.

Guy fives should be celebrated in society and performed regularly.