Chris lost his father's lucky socks, which was giving him good luck when he wore them. To cheer him up, his father says, among other things, "Do you think the Ghostbusters were lucky when they saved New York from the Stay Puft Marshmallow Man?" The episode takes place in 1984, but six episodes later in Everybody Hates Cutting School (2007), which is set in 1985, Chris cuts school in order to see Ghostbusters (1984) at the theater. Since he didn't see it at this point, he probably didn't understand his father's reference.