Just say that one of the managers in your office, someone you had worked with for about 6 years, got everyone in the office together to announce that he was leaving. Imagine that when you saw the gathering, you want to the very man in charge and asked him if you were needed, bearing in mind that you thought it was a work matter and there are some meeting he holds which you need to attend and some that you don't. Imagine he said to you that no, you weren't needed. Imagine that you later find that it was to announce that he is leaving, and that despite sitting opposite you in a north-westerly direction he still hasn't let you know. Imagine you were the only person not invited to that meeting. You've never exactly been close, but then you've never been anything but friendly to each other. You'd assume that he didn't give a monkeys about you, right?
This isn't something I'm going to lose sleep over but that is what could only be defined as a snub, isn't it? I've been snubbed, haven't I?
Should I send him an e-mail calling him a snubber?