... and to women readers, please dont read. Kindly proceed to your kitchen, wash the dishes and bake me some pie, or get pregnant or something. No, seriously. Otherwise, you will hate me more than you already do.
In honor of my crazy friends out there, and as a general public service, I now provide a handy guide to the darker side of Nihongo (because everyone loves to learn dirty words and they're usually the only words in a foreign language we remember or have need to use). This is a list of every bad, dirty, sexual, morbid, disgusting, insulting, profane, and evil thing to say in Japanese that I can rememember at the moment.
Beddo-in suru: "Have sex," literally "do in bed." Alternatives include "futon-in suru" (on a futon) "kuruma-in suru" (in a car), "puburiku preisu-in suru" (in a public place), and my personal favorite, "sensei no tsukue-in suru" (on the professor's desk).
Cheiri boi: "Cherry boy." Aka: virgin. The Japanese picked this up from English and have put it to good use to describe the people who haven't engaged in the activities associated with most of the other words in this list.
Chinchin: "Peepee." A cutesy word for penis. Makes reading "the Three Little Pigs" a particularly hazardous enterprise due to the line, "not by the hair of my chinny chin chin..."
Chinkasu: "Penis dripping." Essentially, this is calling someone "pre-cum." My personal favorite insult.
Chinko: "Penis." If you're a Western male, you'll hear this word used a lot... usually by old Japanese men or elementary school students who are pointing at your crotch. Often replaces "konnichiwa" as a standard greeting.
Hentai: "Perverse." Usually applied to pornographic anime, which politely blurs out the genitals so viewers can enjoy graphic scenes of schoolgirls being brutally raped by tentacled aliens without seeing anything untoward.
Kanyu suki? : "Do you like big breasts?" Sounds very close to "can you ski?" which has probably led to many a hilarious and tragic misunderstanding in Nagano.
Korosu-zo! : "I'll kill you!" The harshest curse in the language, only say it if you really really mean it, or you are having trouble motivating your students to learn English.
Kuso: "Shit." Full form is "kusottare," which literally means "shit water." Sadly, describing a drunk as "kuso no kao" (shit-faced) just leads to confusion here, though "kuso o tabero soshite shine!" (eat shit and die!) gets its meaning across very effectively.
Manko: "Pussy." Not to be confused with "anko," the red bean paste often used in pastries, though doing so is an endless source of amusement for one's co-workers when one announces in the office "mmm, manko ga daisuki desu!" (mmm, pussy is my favorite!)
Nampa suru: "Girl hunting." Used by men when they go out looking to get laid. Successful completion of the mission leads to a triumphant "nampa shita!" from the man in question and a hearty "otsukaresama deshita!" from his friends.
Omae! : "You!" When used among friends this is informal and friendly. When used among people who are not friends, it's exceedingly rude. As such, it's pretty much my standard way of referring to everyone except my friends.
Sekusu: "Sex." As the main words for sex in Japanese are borrowed from English, I can only conclude that either a.) the Japanese had never had sex before the 17th century (furthering my theory that the Japanese reproduce using pods) or b.) were having it so much they just never got around to naming it.
Shikkusu-nain: "69." This word was a godsend as my many previous requests for "roku-ju kyu" were frustratingly met with confusion.
Shine! : "Die!" Can be softened to "doka shinde kudasai," which means "for my sake, would you please go ahead and die?"
Sukebe: "Pervert." Typically applied to Japanese men who are acting sketchy. In other words, "virtually all Japanese men virtually all the time."
Tabechaitai: "I want to eat you out." Aka: cunnilingus, muff diving, licking the hairy fish taco, etc. As Japanese is highly contextualized, this word can also mean "you're so cute I could just eat you up!" when said of an adorable child. Probably best not to say to the adorable children of gangsters, just to be safe...
Yachimai-na! : "Tear them apart!" Yakuza slang used when ordering or encouraging someone to fight. It's like a really violent version of "ganbarre!" Use it at your next Sports Day. It's hilarious.
Yariman: "Slut." Literally means something like "used pussy." The meanest insult directed at the fairer sex I've ever heard. The male equivalent, basically a "player," is "yarichin."
Borrowed from http://funkyblegug.blogspot.com/ thanks buddy