The Haunted House's Infinite Loop

Tang Fei and his girlfriend went into a haunted house, but she disappeared. He called her and discovered that he had somehow gone back two hours in time. His girlfriend said she wasn’t coming, but another friend showed up to meet him, so the two of them went in again. Halfway through, he passed out. When he woke up, he was back two hours earlier once more. Neither his girlfriend nor his male friend had come this time. Instead, his older sister was there.