Never say anything stupid like:
"Nothing has broken yet!"
"I am surprised we didn't just pitchpole"
These seem straightforward, but you never know what you might say if you are thinking it.

First sail on the new boat I went out with my wife for about 30 minutes. I told her we had to go back, but I didn't want to say why. As soon as we were in, tied up, I told her it was because nothing had broken yet.
And... to screw myself next time I go out- I kind of wish I could change my boats name... but I am too superstitious.