It sounds like you have your heart set on doing this. As with Steve, I don't recommend doing it.
The wallpaper will absorbe the moisture and it will be much, MUCH harder to get it off once you paint it. Removing wallpaper is not that hard of a job. It's a little messy and somewhat time consuming but YOU CAN DO IT! Consider searching the Forum once more on How To Remove Wallpaper. (BE sure to read a few posts as there isn't just one post!)
My best to ya and hope this helps. And I hope you reconsider.