My ex’s dad added me on Snapchat ..

My ex’s dad added me on Snapchat a year after our break up.. He always comments on all my stories too and I can’t help but wonder why.. a little back story.. I thought my ex was the one, we talked to our parents about getting married but we broke up because my birth control made me crazy, I took myself into therapy to show him I’m serious about getting help but he slept with my ex bestfriend so I left him alone, a few months after, we hooked up because I loved him🥴🤦🏼‍♀️, I moved to a different state, he found someone new and I removed him from everything in my life.. a few months pass and his dad randomly added my Snapchat.. I thought maybe it was so I could see my dog he kept, but he never talked or brought up the dog.. (my ex and I got a dog together and his dad kept him when we broke up) could my ex be keeping tabs on me? I don’t know why else his dad would be so curious about my life.. especially after a whole year has passed and now it’s about to be another whole year Thats gone by!

UPDATE! He doesn’t flirt with me, nor is he weird in anyway! For example: I will post a pic of dinner I made and he will say “nice” like he seems fatherly in a way, and we never carry on a conversation, it’s always short, friendly and to the point.. I don’t comment on his stories or anything, he just comments on mine..Also! he occasionally posts Snapchat’s of him and the dog so I know it’s him! I’m just kind of puzzled on why he would want to, I really don’t think he has any bad intention!