What does it mean when your girlfriend dream of scratching your mole?

This means that your girlfriend feels that she needs to change something about you but this can also mean that you believe that you have imperfections on your body and that you are uncomfortable about yourself and think that she is uncomfortable about being around you and that type of material.

More specifically, the dream is about the girlfriend's own feelings. The dream suggests that the dreamer needs to improve the boyfriend by removing imperfections. Similarly, the "boyfriend" in the dream also is a metaphor, representing some part of the dreamer's own character that needs improvement, or some area of her life that needs cleaning up.