Wikipedia has a detailed and long post on the subject of profanity. Reading through it I came across this classic section…
“A profane word in one language often sounds like an ordinary word in another; such words are called false friends. Fuck sounds like the French words for “seal” (phoque) and jib (foc), the Spanish words for “seal” (foca) and lightbulb (foco) or the Irish word for “words” (focail), as well as the Latin and Romanian words for “do” (“I do” can be facio in Latin or fac eu in Romanian, which sounds a lot like the English “fuck you”). Arabic for “think” sounds just like “you fucker”. Also, the Croatian word fakat sounds similar to the English “fuck at” when it actually means “factually”. “Fuck” also sounds like the Latin imperative singular form of “do” or “make” (fac) and the Swedish word for “union” (fack); shit sounds somewhat like the Russian for “shield” (щит).
The Cantonese words for “flower” and “bridge”, when said together (“fa kyu”), sound vaguely similar to “fuck you”. Also, the Latin singular imperative of “say” (dic) and the Dutch word for “fat” (dik) are pronounced like the English “dick”. The German word for “fat” is both spelled and pronounced as the word dick in English. And the Dutch word for “cook” or “chef” (kok) sounds exactly like cock. Several European translations of the English word “bassoon” sound very similar to the American English slur faggot; an example is the Albanian “fagot”. Even names in one language may appear as vulgar words in another linguistic community, which causes many immigrants to change their names (common Vietnamese personal names include Phuc and Bich; a fairly common Thai name is Porn. In Bengali, Fukeer is a personal name. In Latin, cum means “with”, but it can be a profane word for “ejaculation” in English. Both cum and precum are prepositions in Romanian but can have profane, explicitly sexual meanings in English.”
and the abbreviation for London Underground Limited (LUL) is the dutch slang for dick – which always makes me laugh anyway!
and also sounds czech “fakt, jo?”, which means coloquially “really?”