油腻大叔 (yóunì dàshū), Oily Uncle. THAT uncle. That completely inappropriate, yet lovable family member - although in China, “uncle” just as often refers to any man around your parents’ age. Family or not, their common trait across cultures is a big and dirty mouth.
While the Chinese uncle-stereotype is certainly crass language-wise (just quiet, please, uncle), the slang name that describes them - “oily” - doesn’t just refer to sleaziness of mind, but also of body. They’re a little sweaty all the time. They’ve reached the age where that belly starts to pop a little further out. They probably wear very visible and unfashionable white socks.
Of course, none of this prevents them from thinking they know everything and bragging about it too. They can (and will!) tell you everything from the future price of bitcoin to what that famous general always used to say. Just smile. They were once like you.
All you need for a good stereotype: Recognizable, and a little mean. Zhihu