Because otherwise Leora would perform every day for the whole week. On the one hand it would be a good thing for us but on the other hand (Paul)... well, it wouldn't be a pleasant situation. Who would accept being able to fuck their girlfriend only when it would be convenient for other people? Let's be clear, even in that case the few times Paul wants to fuck Leora (rightly) he would be criticized to death. So, there has to be a middle ground that doesn't always satisfy everyone.