I know it is a big no no, and everyone will tell me not to do it...but I already have.

And even if I do say so my self the room looks amazing. It is proper bathroom wallpaper, which is designed to be used in a bathroom, it has a plastic texture to it. When you use the shower the water beads on it, but I am convinced in time the adesive will give up and the paper will start to peel off.

Is there anything that can be put over wallpaper to seal it to stop it peeling off? Varnish/PVA/Lacquer????

We've wallpapered our bathroom ceiling... It's been up a year, no sign of any pulling/dropping/peeling.

We did paint it with kitchen and bathroom emulsion, but nothing special.