Killer was a regular high school student and 2 years older than you.

You've liked him since high school, but you've kept your feelings to yourself.

Killer was an excellent student, and you were a good student, and a week before your exams, you asked him for help in preparing. Still, he knew mathematics better.

And so the two of you are sitting at your desk in your room and solving examples.

"Let me check this example with you..."