Can I Legally Say No To My Child’s Grandparents Taking Him Out Of The Country?

Hi, first time posting here. Long story short, my mother and stepfather have court ordered visitation with my son (grandparent rights are a thing here in Oregon). We have a very contentious relationship and in the past they have denied his requests to call us while on vacation with them.

They have requested I get a valid passport for their upcoming vacation with him - they are granted 7 days of vacation annually, either consecutively or broken up. My question is, can I say no to him leaving the country with them? Me and my partner are not comfortable with this at all. There is zero trust in my relationship with them. I imagine they already have tickets and everything booked, but they did not ask my permission to take him out of the country before doing so, and giving me a deadline to have his passport ready. I’ve read through the legal agreement and it doesn’t state anything about vacation or travel aside from the amount of vacation time per year (in addition to other visitation days, and that they are to adhere to my parenting and rules when he’s in their care). They battle me on every little thing they can. I want to be confident I have a legal right to say no to their vacation taking place outside of the country. I have full custody of my son and they don’t pay any child support. My son is 9.

Thank you.