偕老

to grow old together

in company with

prefix used before the surname of a person or a numeral indicating the order of birth of the children in a family or to indicate affection or familiarity / old (of people) / venerable (person) / experienced / of long standing / always / all the time / of the past / very / outdated / (of meat etc) tough

(to live together until the) white hairs of old age (idiom); to live to a ripe old age in conjugal bliss / until death do us part