Containing mold on wallpapered wall (temporary)

Yes, wallpaper off (preferably also the plaster underneath. Do not trap moisture with vinyl. Then possibly just whitewash with lime paint, it does not tolerate moisture, is highly alkaline, and should at least delay new mold growth. Is the boy now old enough to be told not to touch it? If there are still spores or something there...

Yes, he usually doesn't go near it, but I want to lock it just in case so that he can't get to it. We just thought that we could simply order a second changing attachment, then we can leave his room as it is, so he still can't get to that wall, but nothing is immediately against it either. This also prevents jealousy ("why is the baby getting my stuff") and thus kills two birds with one stone.

Still, thanks for your tips; the option to remove the wallpaper and paint with lime paint, as suggested here, could be an additional approach after the baby is born.

That also prevents jealousy ("why does the baby get my things

He learns that quickly and takes care of his sibling without jealousy. The baby also gets "his" mom ;) the "big ones" like to take care of the "little ones"

He learns that quickly and takes care of his sibling without jealousy.
The baby also gets "his" mom ;) ,
the "big ones" like to take care of the "little ones"

Thank you – we are very excited to see how it will be with two. People who have several small children always say, "one is none."
So far he is totally enthusiastic about his "baby sister" in the belly, but who knows how well a three-year-old can imagine that?
We will find out soon, the official ETA is less than 48 hours. ;)

ui, well then good luck and all the best!

Three years apart is already good. Two years is often annoying. But I consider the older sibling taking care of the younger one to be a myth.