When times are good, they don't want to rock the boat.
He is a familiar face and won't rock the boat.
Better not to rock the boat, as it were, he thought.
This is not a good time for you to rock the boat.
Perhaps it was best not to rock the boat further.
"Bob, you've just come up with another reason not to rock the boat right now."
You'd expect him to try to be nice, at least not to rock the boat.
Why would they want to rock the boat in the first place?
But now was not the time to rock the boat.
This small, new person in your life is about to really rock the boat.