You wouldn't come off of your high-horse for anything, would you?
But she was foolish to get on her 'high-horse' and turn down my proposition.
If she'd come off her high-horse the old man might leave a wad to Donnie.
Then he got on his high-horse and told me to shut up or he would knock me down.
Hugh was on his high-horse, and full of historic reminiscences.
The effect I desired was obtained, for he at once fell from his high-horse and became a child again.
originally (late 14c.) "fine, tall horse; war horse, charger" (high steed is from c.1300), also, like high hall, "status symbol;" figurative sense of "airs, easily wounded dignity" in mount (one's) high horse "affect airs of superiority" is from 1782 (Addison has to ride the great horse in the same sense, 1716). Cf. French monter sur ses grands chevaux; "The simile is common to most languages" [Farmer].
To be on one's “high horse” is to be disdainful or conceited: “Sally got tired of Peter's snobbery and finally told him to get off his high horse.”