You know they say little children pay more attention than you think, but this morning I was reminded of it again.
I was on my computer and running rather late when I suddenly realised we had a meeting at work and I couldn't come arbitrarily late—and that even if I left immediately, I would be about ten minutes late! At that realisation, I swore, "Oh flip!"
Amy, who was standing in the same room at the time, picked that up and said, "Oh flip! Oh flip!" a couple of times, apparently finding the word interesting. I'm glad I didn't say anything stronger.
(I'm not sure where I picked up this particular euphemism, but possibly from Elder Rogers, a missionary from Australia, with whom I shared a flat in Cyprus for a while. I think it's not one of the typically Utahn euphemisms.)