Antonyms for the phrase "become husband and wife" could include "separate," "divorce," "break up," or "split." These words imply the ending of a marriage or partnership, rather than the start of one. Other antonyms might include words like "single," "unmarried," or "unattached," which describe a lack of commitment or partnership. While becoming "husband and wife" typically signifies a joyous and celebratory union, the antonyms for this phrase suggest a more unhappy and somber outcome. It's important to remember, however, that relationships can take many different forms and paths, and that each individual's journey is unique.