Teetotalism refers to either the practice of or the promotion of complete abstinence from alcoholic beverages. A person who practices (and possibly advocates) teetotalism is called a teetotaler. Often a Badass character with a Dark and Troubled Past will curiously abstain from drinking with the rest of the characters, usually indicating that * he wants to keep his wits about him; * is a recovering alcoholic, or * his bastard father (and it's always his father) was a drunk. A common prank is to trick this guy into drinking a "Long Island Iced Tea" (which is an alcoholic drink).