IMHO This is not a YPT issue, but a ego PT...
BSA is very careful about ALL events and operations being open to observation by parents. This does not mean "manipulation" but looking on and "being there".
Registration as an adult and taking the YPT is necessary, but no one can deny the parent the right/ability to "observe".
Converstion wih those involved seems appropriate. The CO and COR are to be involved, and IMHO, a Troop cannot have too many WELL TRAINED ASMs... And maybe your local Unit Commish, if you have one.
Right, Fred?