Why did he do this?

I would just really like to understand what is going through my ex’s mind at the moment. We’ve broken up and made up several times before. The last time we broke up was our third break up (5 months ago) He is always the one to break up with me, and always the one to come running back. I usually make it very easy for him to come back into my life, but this time I’m playing very “ungettable”. As soon as we broke up, I unfollowed him on Instagram, but he did not unfollow me and he has watched every single one of my Instagram stories for 5 months. There has been no contact for those 5 months but recently he messaged me on Instagram. He didn’t directly ask to get back together, I assume because he feels embarrassed since we’ve gone down this road before several times. But he did say that I look like this model and said that I look good and asked how I was doing. I didn’t give in to his sudden flirty compliment, but I did reply saying that I was doing well and asked how he was doing, to which he replied very coldly that he was also doing well (I’m guessing because I didn’t give in like I usually do). The conversation ended there, and after that he started liking the pictures that I posted throughout the next few weeks (I’m guessing to get my attention?), something he never usually does when we’re broken up. However today he unfollowed me, and I would just like to know why, after all this time? And is there a chance he might try to contact me again, since he didn’t necessarily block me?

Why are you worrying about this person at all? He's broken up with you three times, that should be enough for you to stop thinking he wants to be with you. If he cared for you like a mature adult he'd still be involved with you instead of prowling around social media like a stupid teenager. Seriously, he sounds like a jerk.