From Longman Dictionary of Contemporary Englishmuck about/around phrasal verb British English informal1BEHAVEto behave in a silly way, especially when you should be working or paying attention to something syn mess aroundStop mucking about and listen!Some of the boys were mucking around on bikes.2BEHAVE muck somebody about/around to cause trouble for someone, especially by changing your mind a lot or not doing what you promised to do syn mess somebody aroundThe company kept mucking us around and changing the price. →muck→ See Verb table
Examples from the Corpus
muck about/around• Blondel then requested the messenger to stop mucking about.• Not now the poor old feller's dead. - Ben, stop mucking about.• They're mostly Northerners, and they don't want to muck about.• You can come up and let yourself go - shout about and that and muck about.• I know he mucks about a bit, but he's a good lad really.• And, as any football-mad kid knows, there is nothing as embarrassing as mucking about in last season's kit.• Not all managers want their employeesmucking around with decisions.• To McDonough, a stubby 280-pounder, the charm of elective office was not mucking about with papers and figures.