The potent mixture of a male’s sperm with a female’s fecal matter after anal sex. Upon pulling out of the anal cavity, a light brown and buttery substance can routinely be seen on ones penis. Hence the term - truffle butter.
‘’You remember that barmaid from the working men’s club, well last night I buggered her anus. After I pulled out, I noticed she had coated my shaft in gooey truffle butter.’’