I was talking to my mum on the phone the other day, catching up on the health matters of various family members. It was entirely inappropriate, then, to hear my sister in the background suddenly hooting with laughter. Bear in mind that I didn't even know she was there up until that point, either.
It turned out that my sister had received a random text message from a friend. A very bored friend.
To be honest, if I got that text, this would have been a little more like my reaction: