Interpreting someone's intentions or feelings based solely on their actions can be challenging, as human behavior is complex and can have various underlying reasons. However, I can offer some potential explanations for why your ex might have been staring at you at the party:
Lingering feelings: It's possible that your ex still has feelings for you, and seeing you with someone else triggered some emotions. Staring could be a way for her to process those feelings or simply reminisce about the past.
Curiosity: After a recent breakup, it's natural for both parties to be curious about each other's lives. Your ex might have been looking at you out of curiosity about how you were doing or who you were with.
Jealousy: Even though she's with a rebound, seeing you having a good time with others may have sparked feelings of jealousy or insecurity.
Regret: Regret over the breakup could also be a reason. Sometimes, after a breakup, people start to second-guess their decisions, leading to mixed emotions when they see their ex-partner moving on.
Habit: During your relationship, your ex might have been accustomed to looking at you in certain situations, and old habits can be hard to break.
Unresolved issues: There could be unresolved issues or emotions between you two that are still influencing her behavior.
It's important to remember that these are only speculations, and without direct communication, it's hard to determine the exact reason behind her actions. If you're genuinely interested in understanding her feelings or motives, consider having an open and honest conversation with her. However, if you're no longer interested in pursuing a relationship with her, it's best to focus on your own healing and moving forward. Everyone copes with breakups differently, and sometimes, people need time and space to process their emotions and feelings.