From Longman Dictionary of Contemporary Englishoverstep the markoverstep the markOFFENDto offend someone by doing or saying things that you should not do or say She overstepped the mark and lost her job. → overstep
Examples from the Corpus
overstep the mark• Helen shrugged; she felt mildly embarrassed, as if she had overstepped the mark.• In either case an agent trying to influence Fontaine may have overstepped the mark.• The preacher overstepped the mark when he called the Royal Mail to a halt on the moor near Bagshot. 