once a whore, always a whore

offensive The belief that someone who has engaged in unscrupulous or immoral behavior, especially for personal gain, will always be associated with it or prone to do it. A: "Well, you know what they say—once a whore, always a whore." B: "Are you kidding me? She gave up that lifestyle a long time ago!" Of course Albert did another ad for that creep—he'll do anything for money. Once a whore, always a whore.