Unless you're a newborn twin, a toddler or character in a horror film, dressing in matching outfits is a bit, well, naff.
But going matchy-matchy is all about showing your love for your other half in South Korea.
The trend is also big in China, as documented by photographer Gillian Bolsover for the Mail Online in 2011.
Lovers Tang Jingzhou and Qian Weisi told her: "This is the way we show our love. We don’t care what others think."