When a group of bros (approximately 22 of them) line up behind each other, and butt fuck. AKA the rooster pen
Sandy: Dude, I can't wait for tonight!
Sandy: Cuz all the bros are wearing their matching shirts while they run a train!
Henry: Yes! I'm in!
Girl: Train banger
Men who enjoy running train. A.K.A the rooster pen
Sandy: Hey bro, have you got your train time in yet?
Henry: Nah, man, but the rooster pens holding a meeting 8pm sharp.
Girl: You guys are such train bangers.