Such a funny way to learn all the words and phrases they don't teach you at Finnish lessons. Although most of the expressions are quite vulgar or obscene language, Finnish learners must know them to survive in everyday situations - especially in the nighttime. There are also frank explanations about some double meanings. Unfortunately the phrase book seems to be very city-oriented and focused on nightlife in bars. But maybe that's the context which is the most motivating for some language learners.
Finnish After Dark is a humouristic look at various Finnish-language terms and phrases that are almost impossible to translate... made me laugh aloud, too.