I like to move it move it

Ah, the joys having boys. I hear Bailey and one of her friends saying, "la, la, la, la, la!" extremely loudly followed by, "Stop it!!!" Needless to say, my nosey self had to go look. There they were sitting on the swing with their hands over their ears. Why was that, one might ask? It was because both boys were standing in front of them, dancing and singing a song to the tune of "I like to move it move it." But my boys, cannot keep things the same, no, they had to change the words to "I like my penis." Yes, my three and five year old, were singing:
I like my penis penis
I like my penis penis
I like my penis penis
I like my...
Penis!!!

This is obviously not from my side of the family...