It's difficult to definitively determine the exact meaning behind your ex's behavior without more context or direct communication with him. However, there could be several possible explanations for his actions:
Privacy or protection of the new relationship: Your ex might want to keep his new relationship private, especially if it's still in its early stages. He might not feel comfortable sharing the details of his personal life with strangers or people he doesn't know well.
Uncertainty or confusion: It's possible that your ex is unsure about his current relationship status and doesn't want to commit to publicly labeling himself as "in a relationship" at this time.
Avoiding confrontation: Your ex might want to avoid potential conflicts or awkward conversations with friends, family, or mutual acquaintances about his new relationship. By claiming to be single when asked by unknown individuals, he can sidestep potential drama.
Sending mixed signals: Your ex could be intentionally keeping his options open or trying to maintain a sense of mystery about his personal life, leading to confusion about his relationship status.
Emotional coping: It's possible that your ex is still processing the breakup or experiencing mixed emotions about the new relationship. Posting pictures with someone else could be a way to move on or make you feel jealous, while claiming to be single might be his way of holding onto the past or maintaining some independence.
Social media image: Some people curate their social media presence to project a certain image or portray themselves in a particular way. He might be trying to present a specific image of himself online.
Ultimately, it's essential to remember that social media doesn't always accurately reflect reality. Online behavior can be complex and multifaceted, and it's easy to misinterpret intentions or actions. If you have concerns or questions about your ex's behavior, the best approach would be to have an open and honest conversation with him directly. However, if you've already moved on from this relationship, it might be best to focus on your own well-being and happiness rather than getting caught up in your ex's online presence.