You know who you can trust today. More importantly, you know who you can't trust. So stick to your guns when a trusted friend asks you to make an exception just this one time and hang out with someone you don't really like. Beg off the invitation and let them know that while they have every right to choose who they hang out with, so do you. When it comes to the company you keep, you have to watch for plotters. There are people who are up to no good.