To act recklessly, unreliably, irresponsibly, or thoughtlessly toward someone or something; to treat someone or something with a lack of respect or seriousness. I know these tabloids play fast and loose with the truth, but they're such a guilty pleasure of mine! I can assure you that I am not playing fast and loose with him; I intend to marry him some day. If you're going to play fast and loose, go work at another firm. That's not how we operate here.