What would happen if i put fresh paint over the wallpaper?Would the wallpaper start coming off?

The wallpaper won't come off if you do the paint job properly. That requires that you prime it with an oil-based primer first. Then you can put fresh paint (latex or not) on top of the paper and you'll be fine. I've been doing this for years in homes we are preparing to sell. Just don't put water-based paint directly onto wallpaper.... that's what will cause it to start coming off...

It's not a good idea to paint over wallpaper altho some people do it. One thing to concider is that if it doesn't look as good as you expect it to, it will be harder to get off once you have painted over it. It probably won't look as smooth either. If the wallpaper is dirty you may have trouble covering some of the area.

It is possible but the wallpaper needs to be primed first.

check hgtv.com or diy.net or just do a websearch on painting over wallpaper for more information.

I have been covering up wallpaper for years with paint, although I would normally wait for a day or so.

I have noticed that it sometimes produces bubbles, which disappear when the moisture dries out.

I am of course talking about water based paint.

most of the times: yes.