This happened a week or two ago, and was too hilarious to not share.
In an effort to learn the Danish language, I set my phone to Danish. My friend was visiting and needed to borrow my phone. I dialed for him and he called up the girl he was staying with. Now, the Danish word for “end” (as in ending a phone call) is, unfortunately, “slut.”
So, at the end of the phone conversation, he remarked on the sillyness of the word before he hit the button and ended the call. Unfortunately, from the other end, the girl heard:
“OK great, I’ll see you soon. Bye. (pause) Haha, slut!” Click.