Should I move on or Stay?

Really if he does that he is just using you go with dave he seams like a nicer guy

Well, I think that the next time this 'Zack' kid breaks up with you be like 'ok, so sine were broken up that means I can date other people now' and see his reaction. Then I would go for dave.

Like he is using you. He sounds like a in the moment type of guy move on and kick him to the curb. Don't be a weekend buddy!

First of all, are you truly "dating" Zack or are you just friends? If he sees the two of you as "dating," he probably would not be "breaking up" with you every week. If he is, he is very immature and not ready for an emotionally stable relationship. If you want a steady relationship, you may not find it with Zack. I would definitely have a chat with him and let him know what it is that you are looking for, and if he is not able to deliver, you definitely have a right to move on. If you choose to stay in the relationship with Zack, you need to be aware that things may never change, and you may waste a lot of time waiting for someone who is "emotionally unavailable. " Also, you are pretty young, so you should be out there enjoying your life and not getting hung up on someone who will not treat you right!