Online lurk

Ok so, last time my ex and I talked was probably December of last year (2018) we had a messy awful breakup decided that talking was bad for us bc it made us toxic regardless we had good intentions. Therefore, naturally we don’t have each other in any type of social media but I’ve noticed that he’s lurk me online. He’s done it a few times after we stopped talking and naturally it decreased as months passed. He never attempted talking to thought. I know he moved out of state for med school because I do too occasionally lurk but it doesn’t goes as far as Facebook. However, he’s been lurking me on Snapchat/Instagram and sees my stories frequently even thought he doesn’t follows me in any of them. Idk what he’s trying to achieve though, I think that if he wanted to say something he would’ve by now...im just curious as in why all the sudden stalking out of the nowhere.