mess around (withsb)
—phrasal verbwithmessverbuk/mes/us/mes/
mainlyUSinformalIf amarriedman or womanmessesaround with someone, they have asexualrelationshipwith someone who is nottheirwifeorhusband.
勾搭（某人），与（某人）有不正当性关系
Shefoundout that herhusbandwasmessingaround with hissecretary.她发现丈夫和他的秘书偷情。