Around that age I had to flat out tell my son that he couldn't do such things because it would be misunderstood and there would be big, nasty consequences in the real world. I was clear that I understand he did it in innocence, but that others wouldn't understand that, and the time to move beyond toddler innocence on all these things was now. Once a boy reaches the age where he can't follow his mom into the girl's restroom, he has also reached the age where he will be expected to keep his personal parts private, and respect the privacy of others by not requesting or attempting to violate it. I told him that in a few years, if he hadn't changed his habits in the area, he could be sent to JAIL for it, it is THAT important to honor privacy. I remember ending a playdate because the two boys ganged up on my daughter and forced her to strip. I talked the same to both boys, and told them again that I knew they didn't really understand why it was serious, but that it was time to learn, and this was why the playdate was over, because it was a message they needed to get loud and clear. If it ever happened again, there would be far more serious consequences.
It took 2 or 3 of those types of things for my son to really "get" it, but - I THINK - he does, now. And, well, he's also "grown up."
These are the sorts of things that worry me most with my AS son. He seems to grow up a year or two behind the scale, and society isn't going to allow for that. The expectations at certain ages are clear, regardless of how relatively innocent any one child may be. Sometimes we're stuck breaking that innocence to help protect our kids.
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Mom to an amazing young adult AS son, plus an also amazing non-AS daughter. Most likely part of the "Broader Autism Phenotype" (some traits).