rock the boat
US /rɑk ðə boʊt/
UK /rɑk ðə boʊt/

1.
波風を立てる, 事を荒立てる
to do or say something that causes problems, especially by upsetting people or by making changes to a situation that is currently stable
:
•
I don't want to rock the boat, but I think we need to address this issue.
波風を立てたくないのですが、この問題に対処する必要があると思います。
•
He's usually quiet and never rocks the boat at meetings.
彼は普段おとなしく、会議で波風を立てることは決してない。