be on (one's) high horse

be on (one's) high horse

To be adopting an attitude of moral superiority. My sister was a troublemaker as a teenager, yet she's always on her high horse, lecturing me about everything. That radio host is known for always being on his high horse, despite the fact that everyone knows he's a creep.See also: high, horse, on

be/get on your ˌhigh ˈhorse

be annoyed because you think that somebody has not treated you with enough respect: When they suggested that she might have made a mistake, she got on her high horse and asked them how they dared question her ability.See also: get, high, horse, on