You shouldn't poke around in your family's private life.
Joe hears that his little sister is dating a boy in his class, and he wants to find out more about it.
Joe wants to know if they have slept together.
Joe has a frank conversation with his sister to ensure she is well informed and able to make good decisions.
Joe confronts his sisters boyfriend and threatens to beat him up if he touches his little sister.
Joe's sister is grateful for his guidance.
Joe's sis is embarrassed by her brothers behavior.