Loving couples say it with matching outfits in South Korea
Online market booms for trend of young couples showing their affection by wearing same clothes
Watch: How couples in South Korea show their love for one another
In a country where public displays of affection are still frowned upon, South Korean couples often advertise their relationship by wearing matching outfits - whether socks, shirts, jackets or, more privately, underwear.
It's especially popular with newlyweds, making South Korean honeymooners easy to spot on Southeast Asian beaches in their twinned T-shirts or shorts and "couple flip-flops".
The fashion can also be seen among young people in China and Japan, but South Koreans have taken it to a different level.
The trend has spawned a small cottage industry, with specialist online stores offering "couple swimwear" for the summer holidays, "couple snowboarding suits" for the winter and "couple tracksuits" for those who like jogging together.