|It sounds like your manager's little favorite is a problem, but the bigger problem is the manager himself. Not only is he showing favoritism, he is taking punitive action based on hearing one side of a story. |
As a first step, you should approach his little favorite and see if there is a way to clear the air with her. Perhaps there was an incident in the past that needs some reconciling, or maybe there are some current work issues that need to be put to rest. This may help stem the flow of venom to your manager, but the prognosis is not great.
The more important step is to meet with your manager to discuss the feedback that he gave you. Tell him that you have thought about his comments and you are somewhat confused. Give him specific examples that show that you get along well with your co-workers, and then ask him for any examples that might illustrate some problems in this area. If he cannot provide any, ask him to give you such feedback whenever he sees an instance in the future.
If you find that he is still mouthing words that his little favorite has scripted, perhaps you and some of your associates should meet with his manager. After all, most senior level managers do not look favorably on favoritism.