My DS (4) and DD(2) bath alone together. We are in and out most of the time getting pj's ready and stuff (and telling them to keep the water IN the bath LOL) They are always nattering and splashing (or fighting LOL) and like others have said I keep an extra ear out for them. It's been a while that we've left them alone to bath... can't remember really.

But I wouldn't just say cos I do with mine that it's ok to leave any 4 & 2 yr old alone. I know how mine play in the bath... and know they're not prone to falling over etc. Not to say they don't fall over ever... we've had some almighty spills before with DS.. usually when he's mucking up, jumping around etc (showing off to us usually) If there's a lot of splashing and jumping I'm in there telling them to settle down.

I'm aware of the dangers with little kids & baths. But I'm comfortable with how my kids are and that we are keeping a good eye & ear on them.