My question involves a child custody case from the State of: NJ

The non-custodial parent was granted supervised visits every Sat from 1-5pm at his mother's house. This was going okay for about 4 weeks. However, recently some events took place and now the non-custodial parent is not welcome at his mother's house. Am I obligated to do anything? Who is responsible to petition for a change in the person that supervises the visits? I feel that the non-custodial parent should be responsible since he asked for visits to begin with. So, do I just leave things as they are and just keep documenting everything? He has not contacted me to discuss an alternative and missed his visit last week.

Thanks for any suggestions,