Son Finds Mom and Her Hot Friend Topless

At my house we have an open door clothes optional policy, my son is old enough to be free around me, he is a good looking guy I am sure he is already having sex. Last week he came home from school and found Joslyn and me outside sun tanning... with our tops off. When he came out he seemed shocked but I wanted to make sure he was not imitated around naked woman, I tell him to come closer and show me what he knows about sex.