Even though i agree with what your son said, yeah thats not good, i have 2 nieces(age 4, 2) an a nephew(1) that i live with, My nieces love this one rap song(livin' in the Projects) they sing the chorus all the time
Living In The Projects
Living In The Projects
Living In The Projects
Broke With No Lights On.

Which is fine for them to sing, an its the funniest thing in the world.

but this one verse that i personally like an sing out loud alot. it refers to his teacher in school saying he wouldnt be shit, an then he says A-town hoe you can suck my dick. so they started saying this. They dont understand it but just an example of how kids listen an do what you do.