a assembly of dudes or bros (4 or more dudes that are at least 16 years old) engaging in group activities like playing video games, playing basketball, or shooting pool until late at night without the presence of females. Generally thought to be gay or immature by those not in the group of bros or those jealous because they couldn't be involved. See the synonyms Bro-Fest if the activities were cool or Sausage Fest if they were lame.
Dude 1- "I'm gonna go to the Dude Fest tonight. Are you?"