From Longman Dictionary of Contemporary Englishrun around with somebody phrasal verb informalto spend a lot of time with someone, especially someone that other people disapprove of He started running around with a gang of teenagers. → run→ See Verb table
Examples from the Corpus
run around with • He ran around with a gang of schoolfriends and was a member of the local swimming club.• He ran around with Kenneth, a huge black runner who drove a Buick Skylark.• I was always out, running around with the guys. 