What does it mean if you find another woman's hair in your bathroom?

First, it would be difficult to know for certain that the hair was from another woman. Second, even if it was from another woman, people get others' hair on their clothing all the time just coming into contact with them. It sounds like there is a concern that your partner is cheating, though, since this was posted in the "Cheating" area and the implication is that this hair you found is from a woman he is cheating on you with. This raises concerns about the relationship regardless if he is cheating or not--because you are concerned this might be a possibility. It would be best to talk with him about these concerns and see how he reacts; don't just assume that he is cheating because of the hair, though, and don't confront him with accusations, because both of these will end up making him defensive and will further break down communication. Hope this helps! Dr. B.