When mom has primary physical and dad has joint legal does dad have 1st right to keep the child when the mother is on vacation.It says no such thing in my court papers. should I be worried?

Depends on your state and county but, if the child is not with you on vacation and the child is left with a sitter, the father still has rights to visitation according to the custody agreement.

What is there to be worried about? It is the child's father and the father has every right to the child as the mother does. The right thing to do is have the father watch the child instead of a third party. You should call your attorney for the correct LEGAL answer.