seven-year itch

[sev-en-yeer]

noun

1. scabies.

2. the temptation to have an affair, held to become a hazard in the seventh year of marriage.

seven-year itch

noun

1. informal,  a tendency towards infidelity, traditionally said to begin after about seven years of marriage

Word History and Origins

Origin of seven-year itch¹

An Americanism dating back to 1895–1900