haha thats cute.
Brandon sometimes says 'yuk' when he is pooing but not all the time.
I have persisted with getting him to sit on it and he will happily for a short time now which is good that he is not afraid of it anymore!!
When I go to the toilet he will follow me in and say 'pot' and sit down himself now, so at least we have overcome the fear, somedays he isnt interested tho but I am not in any hurry.