From Longman Dictionary of Contemporary Englishplay the fieldplay the fieldSEX/HAVE SEX WITHto have sexual relationships with a lot of different people → play
Examples from the Corpus
play the field• Better chance to play the field.• Perhaps because he plays the field.• He gave up playing the field and married a year ago, to a sinewy woman called Cheryl Berkoff.• So she had played the field, enjoying male company without getting in too deep or too seriously. 