Most Helpful Girl
I am a huge believer in confronting the situation head on rather than beating around the bush or worrying about all the possibilities that may or may not occur. The best way to take away all doubts about his intentions/ behavior is to actually speak to him about everything you've said here. I know you don't want to confront him because you're scared of getting hurt but you need to think logically. By not talking to him about this situation, you are making it worse for yourself. Like you said, you don't know where your relationship stands with this guy. If you are serious about this relationship and he isn't, then you need to tell him that. The more straight forward you are with him, the best it will be in the long run. If he is still crazy about his ex or still wants to be with her, he'll keep showing more signs of affection towards her. Soon enough, he'll probably stop talking to you or stop showing any kind of interest towards you and will break it off.
If you don't confront him now, this will go on until he gets tired of it and tells you off. He's obviously acting a little weird so you NEED to talk to him. Also, once you have spoken to him, it will save you a lot of time and misery of stress. Regardless of what the result is, it'll be a load off your shoulders.
Maybe he is confused about his feelings and isn't sure of what he wants. Maybe he shouldn't even be in a relationship with anyone else if he's still uploading pictures of his ex.