It’s a trial, when ladies try to talk about their past romances to their new guy. It’s a test as to how your new man would react to this. Usually, if a guy is totally into you, and you begin talking about how awesome your ex-boyfriend was, he’ll get competitive and he’ll surely start boasting about himself too. Men and their ego.
But, if he doesn’t pay attention about any of what you say about your past romances at all, then it’s a sign that he doesn’t really care about the competition at all. He’s not into you at all.