This morning while we were at a children's music group, a friend of the girls - a boy of about 4 - came up to me while I was talking to another parent. He waited patiently until I was finished, so I got down to his level, said hello and asked him how he was. Quick as a flash he put his hand on my breast, took it away, looked me straight in the face and said "I'm a doctor", then ran off.
The sexuality educator in me was screaming "Experience based learning! Experience based learning!!" ... So after I stopped laughing and shaking my head at his 'creativity', I went to find him and we had a talk about appropriate touch, public and private body parts and respecting ourselves and others.
"I'm a doctor", indeed!