I know a couple of poly people who "discovered" they were poly because they couldn't help but cheat on their monogamous partner and then retroactively declared they were poly. As a poly person, I think of them as assholes who give the rest of us a bad name.
(Oddly the main examples I have in mind are women, contrary to the stereotypes. One man kinda fits but he was basically always terrible at sustaining monogamous relationships in the first place)
