Bradley Cooper mocked by Clint Eastwood!

London: `Hangover` star Bradley Cooper was mocked by veteran actor-director Clint Eastwood on the sets of `American Sniper`.

Eastwood referred to Cooper, 39, as "Her Highness" and "The Duchess" because he spent too long in the makeup chair, reportedly.

"It started because Clint thinks Cooper takes too long in the makeup chair," a source said.

"And lately, whenever he needs Bradley and costar Sienna Miller, he yells, `Are the Girls ready`? When there are action sequences with mud-crawling and fence climbing, Clint jeers, `Are you ladies ready to try that again?` He loves teasing that his star`s just not macho enough," the source added.

`American Sniper` also stars Kyle Gallner and Jake McDorman.