Censorship on radio

em
I was at work the other day, it was around 5pm and the radio was on. I was serving a family with two children under the age of 10 - a girl and a boy. The radio hosts were talking about their boners and "no reason boners".
One of their children then asked their dad what a boner was, and the dad looked mortified and said "I don't know".
It got me thinking, why do we censor expletive language in songs, but have no cares in the world when it comes to talking about things such as boners and sex, especially in the late afternoon when most people are driving home from work?
I understand that these sorts of conversations would be different around 11pm.
Thoughts?