I've had two situations that would sort of qualify. One was a situation in which both sides of a married couple were already long established gamers, friends of one of the group members, and joined up. Apparently there was some sort of unspoken-of problem at home, and She decided to subconsciously vent her spleen about it at our weekly dungeon-clearing hoedown. Everything was cool at first, but as the Secret Bad Thing gained steam her behavoir became more and more noticable. Her characters became increasingly promiscuous (regardless of the situation at hand, toward PCs, NPCs, you name it) while at the same time making a definite effort to distance herself from Him (the husband, natch) in any and all circumstances in game. He'd pick up on this, his mood would sour in reaction, and things would just snowball. It was like watching a trainwreck in slow motion.
Now, we have an annual camping retreat - we gather up all of the extended gaming group, bugger off into the woods for 4 days and nights and game straight through it all. Being part of the group, The Couple is there. The at this point now standard slow-mo trainwreck shenanagans continue. They keep wandering off to have rather pointed conversations near their tent, they pass the first night in camp, get up the next morning, pack their bags, mutter that they're leaving, go, and are never heard from again. Including dropping the friend that first introduced them to the group.
The second instance is actually a bit of a twist. Male gamer, long standing member of the group, etc, meets a girl, decides that she's the one, and in a short time they set plans in motion to tie the knot. Everybody's wonderfully happy for the guy. We don't get much of a chance to meet the bride to be, but, eh, no sweat, they travel in different social circles and they're spending plenty of time together, so it's all good. It later comes out in a conversation that a large part of the reason we havn't had much chance to meet the future Mrs X is because: A) she doesn't know he's a gamer, and B) he's doing his best to make sure she never knows he's a gamer. Now add to the fact that from those rare few meetings we've already enjoyed, we know this lady is really laid back, easy to get along with, and knows we're gamers and has no issue with that whatsoever. Shortly thereafter, we're (that is to say all of us, the people who've been this man's friends and primary social group for the past fifteen years, including his own brother) are declared persona non grata, they get married, and he disappears. They guy basically sabotaged himself. We're still kinda boggling over that one to this day.
