Oh i got a reply from the author of Killer Romance. She said I am talking about another fic by Splashpink who has deleted her account. The stories are a little similar and so a lot of people get confused. In the one I'm talking about Jensen's father is the head of FBI and the series was left at the part where Jensen's ex comes back who is crazy too. She never updated after that. Both the verses are hilarious and creepy!