What to do when someone talks about you behind your back?

She's jealous, and jealousy means we do not own something we think we deserve. We used to think in the 60's about owning somebody else as something bad, but now with the advent of the 21st century jealousy came with vengence. My recommendation is to ignore her. The second thing is, jealousy happen in a triangle: You, him, and her. She probably had her own thoughts about owning him, and she is afraid of losing him now. Therefore, the best approach is to clear out the image for her that he ''the dude'' likes you and what she thought was about owning him was an illusion constructed by her brain.