I have joint custody, but am the primary parent to my child. I've been told by someone other than my ex that he is taking my child out of the US for a "vacation".My ex has never told me about this trip and I hold the passport for our child. Is he required to ask me for permission to take my child out of the country during his visitation? Must I provide him the passport?
PLEASE HELP! His trip is less than 7 days away!
What are my options in Denton, Texas?

He will need the child's passport to get on a plane leaving the country. If he just drives across the border to Mexico, he will still need either proof of sole custody or a letter of permission from you.

...Must I provide him the passport? ...

Of course not.

Why do you ask? Has someone suggested that you have to do whatever the child's father asks you?