At what age can a child ask not to have to go see parent.

Depends on the child, and the parent.

Is your child asking not to visit his/her other parent?

If so, why? Is the other parent abusive, physically or mentally?

How old is your child?

Is this really your child's choice, or yours?

Be honest with yourself and your child. If the child is just mirroring what you say about his/her other parent, then are you really doing what's in the best interest of your child?

If the other parent is abusive in any way, and that's the reason the child doesn't want contact, they it's up to you, the parent, to take the legal steps to protect your child.

The child really never has a choice, if there is a court order the parent with custody is required to supply the child at the time and days stated. If not the non custody parent can take the other parent to court for contempt.

If a child does not want to ( for good reasons) the custody parent needs to file to have the visitation agreement modified