로맨스그레이(1963) / Love Affair ( Romanseugrei )

A respected professor and a company president each keep a young mistress in a second household, until their wives compare notes at their wives' club and march on both apartments together. Shin Sang-ok plays middle-aged vanity for laughs, lets the mistresses argue their own case, and steers both marriages back to shore.

Why it's free: Free on the Korean Film Archive's own channel; KOFA holds the rights to the restorations it publishes.