His new favourite room

The title really says it all: lately, Liam has had a complete obsession with all things bathroom-related. First he discovered the toilet, and the pleasures of sticking his hands into it. Then, after he graduated from the baby tub to the big tub, he began taking a real interest in it; he tries to climb in quite often, not always at bath time and not always without his clothes on. If he wanders into the bathroom while one of us is showering, he has a grand old time pulling back the shower curtain to see what's going on and often tries climbing in himself, not caring at all if he gets wet. Yesterday, he discovered the toilet paper for the first time, unleashing half a roll with just a couple of tugs, and he also managed to flush the toilet all by himself for the first time. I don't know what to do about this bathroom obsession. Part of me is tempted to just shut the door and keep him out of it, which I often do. On the other hand, I take his interest in the toilet as a good thing. Maybe it means we're one step closer to learning how to use it.