What does it mean if your ex is jealous over somebody fancies you?

If your ex is jealous over someone who fancies you, it may indicate that they still have feelings for you or unresolved emotions about the breakup. This jealousy could stem from a sense of possessiveness or a fear of losing you to someone else. It might also reflect their insecurities about their own current situation or relationships. Ultimately, it suggests that they are still emotionally affected by your past connection.