This is exactly what has been happening, actually.
The fellows that I game with have a pretty nasty habit of putting every decision before the whole group. They will even pick up and move each other's minis around interchangeably during combat, and call each other's actions. It makes me crazy and I get on their cases about it a lot, and they will stop for a few rounds...but never for very long.
Well, my girlfriend doesn't like to play that way. She doesn't participate in their discussions of who does what, and she doesn't ask their input when calling her actions. Consequently, she has gained a reputation for not being a "team player" with the other guys in the group. When I push back and tell them to knock it off, they just roll their eyes and mutter something about "special treatment."
So they think I am playing favorites...from their point of view, I am always getting on their case, yet my girlfriend can do no wrong.
It hit fever pitch at our last gaming session, when they started taking votes on what her character should do. She refused, they complained, I interceded, and...well, it didn't go well. You can probably imagine the scene. Raised voices. Threats to quit the game. Accusations of bias and favoritism. Things were said that couldn't be taken back.
There were tons of apology e-mails the next day and every day since. They seem to genuinely feel bad about this and want to make amends, and we are working through it. It is just a really crappy situation, and I wish it had never happened.
Ayway. That's my horror story. I'm feeling a little raw about it still, and our next gaming session is Saturday night. I was just looking for reassurance that this sort of thing isn't unique to my group. But it doesn't seem to be the case.