In a class that involved all the houses in the Academy, the mandated sex education commences to learn the art of procreation especially for the nobility since they have to secure their line of succession to continue their respective houses or families for the commoners.

In an alternate world: Byleth is the professor to teach the mandatory sex education class for the male students. After choosing one eager student for the task, Byleth got more than what she bargained for as the lucky student, in all his eagerness, jammed his dick in her no-no hole.

Not to mention he was a quickshot.