I have a four month old Min Pin that simply refuses to poop outside! I have trained him to pee outside, but we can wait out there for 20 minutes and the second we come back inside, he runs to a corner and poops. Its almost as if he holds it until we go back inside . He gets a firm "NO!" and I make him get a whiff of it, then back outside we go for another 10 minutes, and he just sits there and whines. I keep him in a crate when I can't watch him, but whenever he poops inside, he hides in places where he is out of my view, so I believe that he knows that he is doing is bad. Any suggestions here? This is driving me NUTS!