My 2.5yo son seems ready in almost every single way and is really interested in the potty and toilet and his potty books. The only thing in his way seems to be he just hates having his nappy or trousers off. I'm not sure why, I've never made it taboo, always offer him nappy off time and tell him how nice it is to go without a nappy for a while but whenever it comes off in a nappy change or something and I say do you want to have some nappy free time or sit on potty without a nappy he says nappy on, clothes on and gets upset if I don't and I don't think it's right to push him. He's sat on the potty with his clothes on which i encourage and he's done it a couple of times with his nappy off and got a dinasaur sticker for his efforts but that reward seems to have lost it's appeal really quickely. Help?