Social media w/ SO

My SO has some social media, I barley got a Facebook and only use it to communicate with family that live far away. He doesn't have anything on his fb about me or that he is in a relationship (we've been together over a year)  but still has pictures of his ex on there.
Then he has a snapchat, in the beginning of our relationship we would always communicate through that, but after I found him talking to his ex sexually on there he said he had deleted it from his phone, that was over a year ago. Just a couple days ago I saw his name in snapchat and clicked on it to see that his score has gone up drastically from when he told me he had deleted it (your score only goes up if you send something or open what someone sent you) so obviously he has been on it. When I asked if he still had it he told me no. When I asked him about it again the next day he said he had just got it back that day, so trying to be cute today I sent him a picture and he opens and ignores it but yet his score continues to go up even higher so he is obviously on there and not busy at work like he texted me he was this morning. I feel like he is either talking to girls on both his fb and snapchat or is just ignoring me. Either way it's hurtful and I don't really know how to go about talking to him about it... Advice please?