Ex responding to my text, then ignoring me again. Why is he doing this?

Anonymous
So after a month of NC on my part I decided to text my ex boyfriend on Saturday. 5 min later, he responded with a pic from a hike he was on. He sounded excited in his text. We continued to text back and forth about the hike. I later messaged him that it was nice to talk to him again (he was one to never reply to those). Then just last night, I asked how his feet were because he said he had blisters "the size of Kansas". He didn't respond.

I'm not gonna lie, I was completely surprised.My heart was pounding. I'm still not completely over him, and I miss him a lot. He had told me a month earlier that he was "talking" to someone and that he wanted me to stop contacting him while he was getting to know her. He didn't want to "scare" her off. I respected his space.

I know I should probably not over-analyze, but why would he be so receptive to me, then suddenly just stop? I would hate to think that he's playing mind games. Or is he slowly coming back around?
Updates
+1 y
I need to add that he isn't seeing her anymore. I'm friends with his roommates' gf.
Ex responding to my text, then ignoring me again. Why is he doing this?
4 Opinion