It's generous to let other people use your stuff.
Mario has a house full of things he owns, Luigi came by and wanted to borrow his vacuum.
Mario wants to decide if he should let Luigi use his vacuum.
Mario allows Luigi to use his vacuum, so he can presumably clean his house.
Mario decides that Luigi can't use his vacuum or his other stuff.
Luigi thanks Mario and takes the vacuum and leaves to go clean.
Luigi gets upset with Mario and leaves Mario's house.