Dog question: Why does he do this?

[jimmy d]

Knowing when your dog wants to go before he does it is at least half the battle to house training, and it sounds like you are already there. Do not expect him to go outside when he has to go at this point. You know when he has to go, so pick him up, put him outside where you want him to go and wait patiently until he does. If you keep up this regimen long enough, your dog will learn, and you will be rewarded. It worked for me and my dog!