At first, it may seem that this is a strange sentence. However the interlocutor is clearly familiar with that class of houses whereby one disappears and ceases to be the moment one steps through the door. Given the experiences this person has faced (dearly loved family members, friends and even enemies disappearing into the void) I would say this is a very prudent question.
Wow, I always love the amount of mental gymnastics people perform in the comments to defend this very flawed app. Look, just because this sentence makes sense in some very specific context, doesn't justify its usage over, say, a statement more commonly used in real-life situations, when trying to teach someone the basics of a language.
"stay" implies that there is a longer timeframe in which you want to be there. "Be" is about this moment. Here you might ask if you broke a law by entering or if it is really "your" house in which we are. That is not easy to say without context. And it is not a sentence one would often use in German or English.
I hope I could be of help.