Legal Question in Family Law in California

Re: children

They will attempt to get you to comply with a valid court order but they can't make you.

However, they will make a report of your refusal to cooperate, which can be used against you in contempt proceedings for wilful violation of a court order and in custody modification proceedings to switch the custody to the mother and away from you.

The only reason you should be refusing mom visitation is a danger to the kids. If there's a danger to the kids, you should go to court ex parte to modify the orders to protect the kids. Refusing visitation is not the way to do it.