The are trust issues within you, and there will always be. Everything isn't absolutely lovely if you're feeling the need to spy on him.
He will never be only attracted to you, nor vice versa.
He will look and admire other women..and vice versa with you.
If it's just looking and being appropriate and respectful, I don't see it being a problem...that's my opinion though.
Is it just your self esteem, and you not feeling good enough for him??
You don't mind him watching porn, but you mind him looking at and following women on social media???
If you feel like this is a deal-breaker for you, then end things.
Also, you don't need to nit pick and try to find reasons to convict him, further cement in your head this notion that every guy will hurt you, and to end things. (If that's what you're doing). You can end any relationship, anytime you want to. You don't have to remain.
It may be best to end things if you're not feeling secure in the relationship. You lack trust. (You probably won't ever trust) .and you're feeling that he's just like the rest of the guys you've dealt with..
If you feel that all men are the same, it's probably best if you remain single.