No, besides, his sister discovers that the Rulebook is real

Emma woke up around six in the morning, used to getting up earlier than her brother. The first thing she did was sit up and stretch, yawning, and staring at her brother's bed, she froze, her eyes wide in surprise. There, where her brother should be, was a girl with black hair, just like John, short to the shoulders, her bare C-cup breasts and with panties very similar to her brother's boxers. Emma was silent, thinking, had her brother brought a girl for her last night? Unlikely, John knew very well that she was a light sleeper, she would have woken up very easily, not to mention that it was very, very difficult for him to flirt.

Then she noticed the girl's left shoulder, where there was a tattoo of a xenomorph, John's favorite monster of movie. What were the chances that a random girl would have the same tattoo in the same place? An idea briefly popped into her head, and she doubtfully got up, careful not to wake the sleeping girl, and grabbed the Rulebook, opening it and reading the rules again. "80% of humanity are women ...", that's what John had written, and when she saw the girl in the bed, she had to bite her tongue to keep from laughing. Her brother had never stood out for his intelligence, but he must have realized the risk he was running, since he was in that 80%. Since the Rulebook was real, unless this was not a lucid dream, she took the case from her desk and left as quietly as possible, going to her kitchen.

Sitting at the table, she opened the Rulebook and began to write a few things that John should have written in the first place.

New Rule: The sole and exclusive owner of the Rulebook from now on is Emma Harrison, who is writing these rules at this time.

New Rule: No one but the owner and the previous owner, John Harrison, can view the Rulebook or see the owner write in it.

New rule: Even though John Harrison can see the Rulebook, he cannot write in it nor can he steal it from the owner of it.

New rule: The Rulebook will always return to its owner.

With that written, Emma smiled and began to make coffee for her and her brother ... or rather, her sister.