The movie was announced for the first time in 2005 with Nicolas Cage and Will Smith in the lead roles; when it was delayed several times, both stars dropped out.
As the two couples watch a Mexican wrestling match, Ron states that "anybody can do this" -- the joke being that John Cena, who plays Ron, is a well-known professional wrestler.
The forearm in the left of the movie poster is not John Cenas forearm. His forearms are far far more muscular.