come/get (down) off your high horse

If your sister tells you to "get off your high horse," she means that you're acting snobby or self-righteous, and she wants you to cut it out.

如果你的姐姐告诉你to get off your high horse，她的意思是你表现得势利或自以为是，她想让你不要再那样。

It's time you came down off your high horse and admitted you were wrong.

现在该是你别再自以为是，承认自己错误的时候了。