When someone shows you who they are, believe them the first time.
Of course, I am a believer in second chances, BUT I am also a fan of Maya Angelou's advice. There are very corrupt politicians who showed us who they were before their elections. When someone shows you who they are, BELIEVE THEM THE FIRST TIME. Recently someone was mean to a young person I know who "gave them a pass" because the mean person was feeling sad at the time. Nope, I don't think so. If they are going to try to make themselves feel better by bringing you down, that's someone to avoid.