Reading the stories of children saying things at the most inappropriate moment reminds me of my neighbour. Neighbour has 2 daughters, at the time aged 5 and 3. Her husband travelled for work a lot and she had just had a hysterectomy. Her MIL had come to stay for a couple of weeks while Neighbour recovered from her operation. I went round to see if there was anything I could do to help, and was introduced to MIL. Youngest daughter wandered into the room, ran over to me and gave me a big hug saying brightly "My Mummy's got no fur!"* Cue embarrassed silence on the part of 2 adults, and confused silence on my part as I tried to work out what on earth this meant. Luckily MIL was a lovely lady, and as realisation dawned on me, she quickly took daughters off to help her with something, while neighbour and I collapsed into giggles.
*In case others are struggling as I was see whited text: Neighbour's pubic hair had been shaved prior to the operation