Sandy and Chris

Sandy, one of my two best friends, and Chris, her boyfriend for the second time around (they decided to be only unofficially engaged until he gives her the ring in November or December), are planning on getting married sometime in the next two years, and Sandy has decided that I will be her maid of honor. My only doubt is that I fear Chris has only changed on the surface. I base this on nothing more than my belief that people don't change (unless something shakes their world apart). Perhaps I am wrong. I haven't seen Chris since I told him off at Sandy's 22nd birthday party (and she's 23 now). I hope I am wrong. I suppose it's only natural to feel concern for one's closest friends.