My wife and I have been friends with Dan since high school. When she and I hooked up in 2005, it seemed only natural to invite him along on many of our outings. He was single at the time and remained so until just this year. I figure that my wife and I spared Dan plenty of Friday and Saturday nights by himself. Even though being the third wheel isn't always fun, it sure beats not having anyone to interact with, right? Dan finally entered into a relationship about 3 months ago, and it's as though he has fallen off the map completely. He's hardly active on Facebook and doesn't deign to call or text me, even occasionally. The Dan from before is no longer. I'm trying not to take it personally and reason that maybe he'll come around again once the honeymoon stage he and his new girlfriend are in tapers off. To be frank, I feel a little cheated -- almost as if he's stolen something from me. What that something is I can't quite put my finger on. Maybe i...