#privateparts

How do we speak to our child about touching private parts so that they feel safe and open with us enough to share?

Our child has had two incidents at school in the past two weeks that we are very concerned about. The first time they exposed themself at dismissal to their classmates after being dared by others. The second time they were sitting in a circle with their peers and reached a hand up another child’s shorts. The child was very alarmed and upset of course.
There is no open access to the internet. We are starting to look at the time that has spent on FaceTime with the best friend that moved away.
Could this other child have been exposed and shared this with our child?
How do we speak to our child about this so that they feel safe and open with us enough to share?