Someone who will not stop talking about, or who only talks about, religion. The type of person you dread being around because of their single-gear, close-minded conversation skills.
Imagine someone who only talked about beans; lima beans, green beans, black beans, pinto beans, garbanzo beans, kidney beans, mung beans, soybeans, etc. Sounds awful, doesn't it?
"Grandpa John will not shut the fuck up about the bible. He is such a bean guy."
A reference to doggy style gay sex where the pitcher's abnormally long balls (bean bag) swing in a pendulum like manner and strike the underside of the catcher's fleshy meat sac (bean bag).
Gay Guy 1: "oh my cubes are so bruised from that vicious game of bean bag tag last night."