Why can no one in manga ever explain that weather or not the other party would intentionally break something is not the problem, it's a size, logistics and/or material problem. It seems it's solely for drama purposes in like all manga.
"I want in"
"No"
"but I'm not bad!"
"No you're not but the floor can't hold your weight and will break which might hurt you. I'm worried about your safety and we would need to further work on the house to accommodate you."
How hard is that?