Thread:Derp23/@comment-26385595-20170909220857/@comment-5231983-20170914223906

One day, a girl goes to her grandfather's funeral, and there she meets a boy. She really likes this boy, but she doesn't get anything to contact him (like his phone number) and doesn't learn his name. She asks around, but no one can identify him. The next day, the girl kills her sister. Why?