Once Luke had his nappy off tonight he went across the room & fetched Jack's potty. He put it down and with some difficulty managed to sit on it - beaming with his own cleverness. I made a 'ssssss' sound which he thought was hilarious and he came and gave me a hug before returning to sit on the potty again to be following by more sitting, 'sss'ing, laughing, coming for a cuddle and returning to do it all over again ... and again ... many times.

After a few goes he started prompting me to make the 'sssss' sound.