My waters broke in bed but I had time to jump into the ensuite before there was a gush. You can by waterproof matress protectors, they are very plasticy and noisy. I have them on my DD's beds and then have a quilted matress protector ontop so its not noisy or uncomfertable. If they have an accident then i need to wash the bedding a 2 matress protectors but much easier than cleaning the matress

I think only a small percentage of women have their waters break before or at the onset of labour, most of the time you will have contractions first so will have time to throw some extra towels on the bed if you want to lie down. I was one of the small number of women who had their waters break before labour, in bed both times!