Indy singing with Daddy

The other night I was cleaning Indy's room and putting away his laundry and I hear him making noise in the living room while Kevin is playing his guitar.  I turn the corner and see Kevin singing over Indy.  I realized Indy wasn't fussing he was singing with Kevin.  Kevin said they do it all the time and Indy just plays with his feet and sings along.  I wish I could have got a picture of his face but as soon as he would see me he would stop.