Ex wants as reaction. why?

Ex broke up with me a while back. We do go to the same gym so we see each other a lot. Was hot and cold, flirted with other guys in front of me... technically played a lot of mind games in the beginning of the break up. Which was 4 months ago.

Now, things have gotten quite unusual. Whenever I talk to a girl, she would stare and whisper with her girlfriends. My friends and I definitely agree that she is stalking me at the gym, doing the classes that she usually doesn't do, which is something I do. Stares at me. Last week, she liked my instagram post but didn't like the one this week.

What's up with that?

someone explain this behaviour?
Ex wants as reaction. why?
Add Opinion