The phrase "billed and coo" is often used to describe affectionate or lovey-dovey behavior between couples, particularly birds. Antonyms for this expression may include harsh, argumentative, or distant behaviors. Words such as confrontational, argumentative, or indifferent could be used to describe relationships where partners are not affectionate or loving towards each other. Some other antonyms for "billed and coo" could be averted, disdainful or stoic conduct. These antonyms describe relationships that lack any form of intimacy or affection - quite the opposite of the playful and romantic behavior that is typically associated with the phrase "billed and coo.