Some signs you may have over-involved your three year old in a recent bathroom renovation...
Mid shower/dinner/phone call, you are interrupted with questions such as "where you want yoo towel wail, Mum?" "Woo want the handle on the left or the wight?"
They complain that their own perfectly fine bathroom is getting very old and needs some work.
When he/she can sense they have made a mess/mistake they sweetly say "Your noo baffroom looks so nice, Mum."
When they are feel hard done by (read disciplined) they utter nasty things about "woo baffroom not good one" as they're walking to their room. (Is so a good one, Magoo.)
They don't want to leave the plumbing store.
They want their own paint roller and squeegee for "Kissmas".
He/she takes a leaf out of their father's book and accidentally locks him/herself in the bathroom they are working on while you natter on the phone.