It's difficult to say with certainty why your ex acted the way he did when you bumped into each other. People's emotions and reactions can be complex, especially after a breakup. However, there are a few possible explanations for his behavior:
Guilt or Embarrassment: Your ex might feel guilty or embarrassed about how he ended the relationship, particularly if he broke up with you over text. Running away could be his way of avoiding confrontation or uncomfortable feelings.
Regret or Sadness: Seeing you might have triggered feelings of regret or sadness about the breakup. Running away could be his way of coping with those emotions.
Avoidance: Some people find it difficult to face their ex-partners after a breakup, especially if they know the other person is hurt or upset. Running away might be his way of avoiding any potential emotional conversations or discussions about the past.
Fear of Rejection: He might fear that you are still upset with him and that you may reject or ignore him if he approaches you.
Desire for Space: After a breakup, some individuals prefer to have space and distance from their ex-partners to heal and move on. Running away could be a way for him to maintain that space.
Uncertainty: If the breakup was recent, he might still be processing his emotions and trying to figure out how to handle interactions with you.
Social Anxiety: In some cases, individuals may have social anxiety or discomfort with certain social situations, which could lead them to react by running away.
Ultimately, the specific reason behind his behavior can only be known if he chooses to share it with you. It's important to remember that you have no control over his actions or emotions. What you can focus on is taking care of yourself and your own well-being during this time. If you find that running into him is causing you distress, it may be best to continue avoiding contact and giving yourself space to heal from the breakup. If you feel overwhelmed by the situation, consider talking to a close friend, family member, or a therapist who can provide support and understanding.