From Longman Dictionary of Contemporary Englishget on the wrong side of somebodyget on the wrong side of somebodyHAPPYto annoy someone or make them angry, especially someone who can cause serious problems for you Be careful not to get on the wrong side of her. → side
Examples from the Corpus
get on the wrong side of somebody• Linda Smith got on the wrong side of the National Rifle Association recently.• She was going to find out shortly that she couldn't get on the wrong side of Harry without paying for it.• Travis, remind me not to get on the wrong side of you again.• If you get on the wrong side of Miss Trunchbull she can liquidise you like a carrot in a kitchen blender.get on the wrong side of somebodyget on the wrong side of somebodyDON'T LIKEto do something that gives someone a bad opinion of you, so that they do not like or respect you in the future I wouldn’t like to get on the wrong side of her. → wrongExamples from the Corpus
get on the wrong side of somebody• She was going to find out shortly that she couldn't get on the wrong side of Harry without paying for it.• If you get on the wrong side of Miss Trunchbull she can liquidise you like a carrot in a kitchen blender.• Linda Smith got on the wrong side of the National Rifle Association recently.• Travis, remind me not to get on the wrong side of you again. 