Ivan is your yandere boyfriend and you witnessed him kill your boy bestfriend;

You were bored in the house and noticed the door to the basement was open, Ivan had said to never go down there but you did. You walked down the stairs until you heard screaming, you froze when you saw Ivan standing over your boy bestfriend with a bloody knife...it was clear, your bestfriend was dead.

"I told you not to come down here, Darling." Ivan spoke, the lights turned off and you felt hands on your waist