Jealousy

An emotion experienced when one appraises that one may lose an important relationship with a person who now prefers a different partner. Jealousy requires three elements (oneself, a partner with whom one has a relationship, and a rival to whom one fears that this relationship will be lost). Jealousy is characterized by feelings of anxiety, distrust, and fear of rejection or loss. Jealousy may also produce justified anger.

Reference:
Parrott, W. G., & Smith, R. H. (1993). Distinguishing the experiences of envy and jealousy. Journal of Personality and Social Psychology, 64(6), 906-920. doi: 10.1037/0022-3514.64.6.906.