Most Helpful Girl
You need to decide for yourself if he's the guy you wanna stay with, if he's not, then don't waste any more time and break up. You do need to think about it though. The picture was probably the last straw? Because pictures online can pop up at any time again in the future.
Do you love him and do you see a future with him? If you do and you want that future, then go for it and try to talk with him and come to a point where the relationship is good for both of you. You're in this relationship together, not just you or not just him.
If you don't see this going anywhere and you do want a serious relationship, think about whether the relationship could be serious with him. If it can't, I think it'd be best if you break up. If it can be with him, I suggest you talk to him.
What I basicly mean is: if you want him and you feel there's a future for you both, talk with him about his behavior and how you want it to be (though be realistic). If you don't feel it's going anywhere, you could either try and talk to him or break up with him.