Gravity Is A Hairy Subject.

My son and I had a bath together, I generally try to bath him on his own or with daddy because he's four and I feel a bit funny sharing a bath with him now he's gotten older.
Anyway as soon as he got in the bath he crouched down and started to pee. I was in the bath and he peed in my lovely hot bubbly water. Not impressed I made him get out and use the toilet.
When he got back in he had to suffer a forceful lecture at how we use toilets for peeing and baths for washing.
When I had finished and stood up to get out the bath he started protesting that I was peeing in the bath.

I wasn't. Let me make that clear.

Now in that personal lady area so beloved my males and dogs once a month I'm not bald, there's no landing strip cos that would take time and effort to shave or money and pain to wax. The water runs down my body and drips of the hair. ok? You with me here? This is what my son saw and this is what he thinks was me peeing.

How do you explain gravity and pubic hair to a four year old?