Oh, blueteddy, snap! Ds2 is 2.8 and is also terrified of the potty and refuses to sit on it fully clothed, never mind naked! Same with the toilet. Dd (4.9) got him to sit on the potty a while back, but he won't do it now, and I've had her and ds1 (6.9) demonstrating for him, but all to no avail. He doesn't even like running round with nothing on. A couple of times he's not wanted to get in the bath because he says he needs a poo ("poo coming out mummy!"), but will he sit on the potty? Will he heck!
It's very annoying because clearly very aware and will come and get me to do his nappy if he's dirty, in the middle of the night a couple of weeks ago! But won't co-operate with training. Am currently letting it go, I think til after half term and then will try again.