My youngest was about six months, somewhere around there, and I had placed him in his little baby carrier seat while I took a shower and left my 3 year old to watch tv. Anyway, not long after I was in the shower I could hear giggles and I asked DS, "what was so funny", to which he replied, "I'm playing with bubby."
I panicked, looked out to see my oldest had the baby, feet first in the potty, flushing it. I shrieked, "what are you doing?" My DS said, "I'm showering bubby." They both were giggling.