This sort of thing has happened to me a few times in my life (luckily not any time recently), and it is always devastating to me when it does. When I was much younger and much worse off socially, I used to hang out with a group of people before school that I thought were my friends. I used to listen to their conversations, but I hardly contributed myself. One day, after a few months, one of them came up to me and said "You know, you can stand near other people...you don't always have to stand near where we are". It dawned on me then just how bad my social skills at the time were, and just how little they cared for me, it was pretty rough.