I ask because my sisters new partner keeps saying his exs are 'Fing idiots'. I have heard before this being mentioned as a red flag. But if his stories about why they are stack up (says one a cheat one messed him about blah blah blah) then is it still a red flag. And why? I just feel uncomfortable about why he keeps saying this to my sister everytime they talk about their past. She doesn't mention her exes (idiot or not)