Hello, I visited my girlfriend in Australia. She is living in a share house and I slept in her room in the same bed for two nights. I arrived 3 weeks ago but my girlfriend and I travelled so I wasn't in that apartment neither were my bags. Just now, I want to stay for 1 week more before I leave. The owner wants her to pay for 4 weeks even though in total I will only be here for 1.5 weeks. She insists that I pay 100$ for every week so in total 400$ for a shared single bed in my girlfriend's room for which she already pays 150$ a week. How is the legal situation under Property Law?