Captain Cornhole is what you call a guy who is a BIG asshole! Simply calling someone "Captain" is enough if everyone around already knows what you are talking about about.
Gareth: I just saw Cornhole Canyon last night.
Jalapeno: Woah, really?
Gareth: Yeah, it gave me lots of ideas of what I could do with my boy...umm girlfriend.
Jalapeno: Gay, much?