It’s hard to comprehend how badly this could go. I assume this was a search carried out by the father. Good luck to him.
If it was the girlfriend, she should consider how deep her feelings are for the father. If it’s just “one of those things” she might want to start running now.
Other recent searches: “sociopath son blackmails mom”, “how to blackmail to get sex successfully”.
Sociopath world is a tough, tough place. Sociopaths/psychopaths move though the world like sharks through the water. Invisible sharks. Somehow nobody can see them. Naive prey syndrome, naive prey disorder, naive prey psychosis.