Arrggghhhhhh - please help me!

[Alibabaandthe80nappies]

DS1 is just 3, and we have been potty training for 2 weeks.

As long as he is completely naked then he will go to his potty of his own accord, but only wees not poo. When he wants to poo he waits until I'm out of the room and then poos on the floor.

As soon as I put pants on him, he just behaves as if he has a nappy on and wees in his pants and onto the floor. Sometimes he will stop and go to the potty, but mostly he doesn't.

I can feel myself getting really stressed out about it. I don't want to go out anywhere because I think having a pull-up on will just confuse him even more. He never, ever says 'Mummy I need a wee' or asks for the potty.

Half the problem is that he gets so engrossed in what he's doing that I think he just forgets about it, and I struggle to get him to focus and talk to me about it for a minute or two.

I remind him every 10-15 minutes.
I have tried putting the potty in the downstairs loo or the bathroom so that he can do a poo in privacy but he still goes on the floor.
We have read books, I leave the door open when I go to the loo and he is welcome to come in and so does DH when he is here.

Help!