The man - surnamed Zeng, who was on an outstation assignment to Liuzhou in Guangxi province, bumped into a prostitute at Jiangbin Park.
In dim lighting, he saw that the woman was quite pretty. He gave her 60 yuan (RM28) for a round of sex.
Just as they finished having sex in a room at a back lane, police ambushed the premises.
Zeng jumped out of the window in an attempt to flee but was arrested, while the prostitute, surnamed Tan, was detained in the room.
As the pair reached the police station, Zeng was shocked when reporters told him the prostitute was a 42-year-old man.
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