The guidelines suck in this case, in my opinion. The primary custodial parent, I believe, has the say so. But, having joint, if the child wants to be involved in the activity that you enter them into, I believe that you are forming a case. You are supposed to be involved in the selection of activities. You should always be informed of any (verbal, or written) communication that you are not able to get on your own. If the other parent has them in an activity and does not inform you of the many notices that are usually given, you are not being included in your childs life the way you should. As far as the noncustodial parent trying to allow their child to partake in an activity that you both enjoy.... I think you have a case to speak with council. You should be able to get a 30 min consultation with an attorney through an employer or just look in the phone book. It is often offered. I tried to get my children in preschool. The other parent called it "Freakin DayCare" that set the ball rolling for me.