His kids take off his thick skin completely (the leather jacket) and that scares him
he takes it back quickly by being abusive/mean to them.
He has his thick skin back on, but he feels bad how he treated them when he was scared
soon after, he apologizes and tells his kids he loves them.
That takes off the layer of thick skin and in the next scene he has a jean jacket on, his thick skin is gone again, but he's not
completely vulnerable