Painting Textured MH Drywall

We rent a DW where our LL allows us to be creative (but not wild), in decorating our homes, and painting as we wish.

The BR's in our rental have the engineered wallpaper built into the drywall. I am hoping to surprise my 3 year old who is on vacation with my husband in Ohio for a week, by remodeling his room with all of his Cars2 deco. The walls are an off-white with a floral texture, and the ever-slightest hunter and plum wide-set pinstriping.

I'm wanting to paint the room a light grey. Not a sheer grey, almost the shade of when you LIGHTLY sketch with a pencil. I used primer on 2 walls in our master bath(Killz), when we redid that room, and both of those walls peeled. YET, the wall I DIDN'T use primer on, didn't peel at all.

So, my question is, I know I will have to double coat the room anyways, but do I really need to prime? I know I've said in my bathroom, I got lucky and some walls w/o primer were fine. But I'm a little worried that I won't get so lucky. Any advice?

I'd prime. It's thicker than regular paint is and will almost smooth that wallpaper for you.

well, after the disaster using primer in our master bath, i used primer on the smallest wall in the room, which is the bump out closet...then i painted the WHOLE room...sure enough, the wall with primer, started peeling immediately...this time i used the brand with the target on the front, from home depot(idk the brand, i gave it to the neighbor)...in the master bath, i used killz. so primer doesn't want to work on our walls. the walls where i DIDN'T use primer, are perfect. i even did awesome with the Blue tape, since i did the walls 2 different colors

now, too bad when i chose dark grey as lower half, and white on upper, that the term "mental facility" didn't come to mind. instead, i was going by a Cars2 theme. not til tonight, when my 14 year old neighbor said she felt "like she was in county", did i see the error of my ways...*eye roll*

alas, oh well...it will hopefully look MUCH better, when those 20 or so cars decals and framed arts go on the wall...oh, and i used a paint scraper on the bump out, and just did 2 coats of white paint, and it's fine now. the closet walls are white, with the dark grey door, so i could hide a huge dent in the bottom of the door panel.

I can't understand why the primer would peel. I've used Zinsser Bullseye and "Cover Stain" primers for years and have never had it peel. And their customer service has always been great (for me anyway). You can contact them at 887-385-8155.