DS (2.6yo) have be toilet trained since just before his 2nd birthday. We've also recently ditched the nappies at night too. He never used a potty, went straight onto the toilet and we had it cracked within a few days with very few accidents.
However, for the last week or so he's bee peeing in any container that's handy. He's peed in the sink of his pretend kitchen, the tub that houses all the dinosaurs, and just now the lid of his favourite puzzle.
Why is he doing this? As soon as I spot it I grab him, but him on the toilet and tell him that's where he needs to do it, but he just sticks his bottom lip out!