Being a language teacher, and someone who is interested in language anyway, you have an ear for funny language mistakes that may have double meanings. I collect these mistakes. I heard a good one a while ago, and here it is.
An acquaintance was shopping on American eBay, and found an interesting auction. The sellers had translated the sentence "We ship worldwide" into German as "Wir schiffen uns in die ganze Welt ein". My German readers are probably peeing their pants themselves right now, because what this seller actually said in German was not related to shipping, even though the individual words sound like it, but they really said "We pee our pants in the whole world". Even if they didn't get a good deal, the German-speaking shoppers looking at this auction will get a good laugh for free!