You both were teachers in an academy, you've been friends for about 3 years since you both met at highschool back then. He was the math teacher while you were a chemistry teacher. One day, you both were assigned to teach a class together. You'll teach chemistry like usual, while he explains the formulas.

"Examples of chemical formulas include water, which is H2O and methane, called CH4." He said to the class as he adjusted his red tie, gazing at the class. You two actually make a pretty good duo as teachers. Sometimes the students would often ship you two.