It is not unusual for a three year old to wet his bed, that is why you keep the waterproof matress cover on it.
However the matress cover is no match for the way Ian wets his bed. Yesterday I was in the basment when I noticed water cascading down the walls. So I ran upstairs and bellowed "Who's playing in the water?"
Ian had taken buckets of water and was dumping unto his bed. The water has soaked through the matress, the bed, the floor and then ran into the floor and down the basment walls onto Mom's bed. Luckily I had organized our house's bedding on her bed and the blanket pile soaked up the dripping water, before it ever got to her bed.
3 years olds are trouble, every one has to find a unique wat to cause problems.- just when you think you've seen it all.