Tell me to block them during the summer, but showing back up out of nowhere

So there was this boy so I am gay right so there was this boy during last year I started talking to and we flirted a little bit he was acting like he didn’t like me, but he was still flirting back and a lot of things that I said he used to talk to other people about, but he didn’t at first like one instant when I was talking to him the thing that I told him, he kept a secret into people saw a notification of texting him and he showed them the text message but that was OK so then during the summer when I texted him, he texted me and told me to block him and delete the number because he has a girlfriend, but me and my friend said that he does not have a girlfriend so I did exactly that I blocked him deleted the number and everything so tell me why yesterday was the first ever time I saw him since that happened and I think he saw me because I was walking right next to him so tell me why when I get home and I look on Snapchat I see that he has followed me and added me back and it says that happened two hours ago the same time around when I seen him so I texted it but he didn’t respond. He left me on delivered so now I’m like I know this has to mean something like I just need some help like what is this supposed to mean? It is giving mix signals.