Ting Su, 29, was suspicious that her husband was cheating on her, so she followed him to a shopping centre using a mobile phone tracker.
But nothing could have prepared her for what she was about to discover.
Her husband, Cheng, 30, was completely naked inside his car - and, bumping and grinding right there along with him, was Ting Su's twin sister.
Horrified at being discovered, they both jumped out of the car with not a thread of clothing - presumably in a bid to comfort Ting Su and try to explain themselves.
But, spotting her opportunity, the heartbroken wife hopped into the car and drove off, leaving her love rat husband and traitorous twin standing naked in a VERY public car park.
Witness You Meng said: "It was so funny. Loads of people were grabbing their phones and I did as well.
"He was banging his fist on the window and shouting at her, and she just wasn’t playing ball."
Photos of the disgraced couple are now all over the internet - obviously - and Ting Su, who recently gave birth to twins of her own, has filed for divorce.