This phrase is used to intensify the meaning of verbs such as
bore or charm or kid or scare or talk . For example,
That speech bored the pants off us, or
It was a real tornado and scared the pants off me. Playwright Eugene O'Neill used it in
Ah, Wilderness! (1933): "I tell you, you scared the pants off him," and Evelyn Waugh, in
A Handful of Dust (1934), had a variation, "She bores my pants off." [
Colloquial; early 1900s] Also see
bore to death;
beat the pants off.