Dad, Mum and horses

Little Johnny attended a horse auction with his father. He watched as his father moved from horse to horse, slowly running his hands up and down the horses legs and rump, and chest.

After a few minutes, Johnny asked, "Dad, why are you doing that?"

His father replied, "Because when I am buying horses, I have to make sure that they are healthy and in absolutely good shape before I buy."

Johnny, looking worried, said, "Dad .... dad ... I think the Milkman wants to buy Mummy."