I leave DS alone most of the time, I trust him, he doesn't do anything stupid, just sits there with his cars and drives them along the side of the bath.

I do pop out to get their jarmies and set up their nappies whilst both are in there (so 11 months and 2.5 years) but I can hear them playing, and it would take me a second to get there incase something went wrong anyway because my house is tiny.

DS does not touch the taps, he knows its naughty. He also tells DD off for touching the taps if she tries to touch it too

I think it totally depends on the child, and nobody knows them better than their mother.