Dreams involving ex-partners often reflect unresolved feelings or past experiences. In your case, the dream might symbolize a few things:

1. Emotional Conflicts: The presence of your ex could indicate that you might still have some lingering feelings or thoughts about that relationship. It doesn't necessarily mean you want to go back, but your subconscious might be processing those past experiences.
2. Jealousy and Insecurity: Your current boyfriend's jealousy in the dream could represent your own insecurities or fears about your current relationship. Perhaps you worry about how past relationships could affect your present or future partnerships.
3. Communication and Boundaries: Your attempt to explain your feelings in the dream highlights the importance of communication in relationships. It could be a reflection of your desire for transparency and reassurance in your current relationship.

Overall, this dream might encourage you to reflect on your feelings about past relationships and how they influence your current emotional state. Consider discussing any insecurities with your partner to strengthen your connection and build trust.