Our house has a magical scary box of water. Yours probably does too.
La Doof Kitton is concerned about this scary box of water and why mom subjects herself to it...so he involves himself in it's filling. (And then, since he has made it a habit to consider falling in, he gets kicked out of the bathroom while mom takes her soak. (because as we all know, a cat falling into an occupied bathtub leaves one with legs that look like they lost an epic battle with a blender.)
There is a slow progression...from side-of tub sitter...
to "stalking the razor" kitteh
to "balancing precariously kitteh". He is quite talented at balancing (there are zero feet on the sides of the tub in this one):
And it tends to end with "ooh, lookit, I just dumped in more bubble bath for ya ma!"
(and this would be the point at which he is escourted out of the bathroom and the door is closed.)