Yeah, I will probably get blasted for this, but children play dress up and may put on high heels, etc., for fun. If this was teacher directed, then it isn’t innocent OR fun.
Many years ago we had a party for a group of 7 year olds. As all the kids were going out side after playing in the house one of the little boys was in the playroom looking at the girls dress up clothes. They were very fancy bridal gowns. He asked if he could try it on. I said yes. And he quickly put it on over his clothes. He came from a plain dress home. I don’t imagine he ever saw sparkly clothes before. Then he took them off and ran ot to play in the snow with the rest.
He works in the trades now. And he is doing well. Little kids are physical beings and have to get in or on or some how process new things physically. It doesn’t mean they want to own it. Just understand it.
A 3-year-old boy might put on high heels, but by 5 they would not choose to do so. Adult manipulation.
That man should get his boy out of there ASAP.