Can my ex husband stop me and my son from moving out of state?

He can try there is a prescribed legal process for relocation, and must be followed to the letter. Consult an attorney in your area before proceeding any further.

He can take you to court and ask for your son to not leave the state. You may actually have one of those cases where the court may let you leave. Frankly, I suggest you file and ask the court for permission and present your best case why it is in your son's best interest to leave. That way you can frame the case you want and not appear to be somebody who ignores court orders.

In OK, if a party wishes to move more than 75 miles, either in state or across state lines, either the two parents come to an agreement, or the matter gets presented to the court and the court will make the decision.

Yes, he can take you to court - that does not mean he will win. Unfortunately, move-away cases are time consuming and costly. You are far better off talking immediately (even for an hour) with a family law attorney who can review your orders and give you advice specific to your case.

I'm sorry to hear about your situation and how your ex is threatening to make things as difficult for you as possible, especially given his track record on visitation for the past 4 years. You mention "divorce papers" but then also mention "agreement". It will depend on whether you have an actual separation agreement/custody agreement vs a court order/divorce judgment which INCORPORATES an agreement when it comes to enforcing the terms or if either side wants to change it. But either way, you should first start with consulting an attorney to simply review the actual document to confirm what it actually does and doesn't say. For example there is a big difference between mere notification of a move vs consent of a move. Also, if the document is silent or ambiguous regarding specifically moving out of state (not simply a change of local address), then he can likely file with the court to TRY and prevent the move and otherwise state his objections. But then it would be up to the judge to review the facts, evidence, and credibility of the witnesses to see if the move would be in the best interests of the child. You should consult an attorney.

Yes. you are not entitled to leaver unless you have his agreement or a court order allowing you to leave. Those are not simple proceedings. You have to be able to establish, among others things, the reason for you leaving is to improve you and your kids lives, that the removal is not being done simply to defeat his rights, that the kids lives will improve by reason of the move. So no you can not leave.