How can I stop this?? He is still in nappies obviously, but before he goes to sleep will poke his willy out of his nappy and a few hours later will wake sobbing in a damp patch. He's just moved to a bed and the thought of having to keep changing the bed every single day is getting me down. I bought hippychick matress protectors which seem very good, but how can I get him to keep his hands out of his nappy??