An implied individual has ceased being pleasant, and will now resort to unpleasant means to attain their objectives.

(idiomatic) People who are decent, friendly, and agreeable tend to be unsuccessful because they are outmaneuvered or overwhelmed by others who are not so decent, friendly, or agreeable.

Alternative form of no more Mr. Nice Guy

Alternative form of no more Mr. Nice Guy

A stressful form of cognitive dissonance among employees whose work involves assuming a fake cheerful persona to deal with members of the public.

(humorous) Expressing reproach when somebody harms or damages something.