Rich Man, Poor Man (1976)

S5E6 Prick Up Your Ears

Lois realizes that Chris has been misinformed about sex, prompting her to step in and teach a sex education class at his high school. Her candid approach, however, ruffles some parents' feathers, leading to her replacement. Shortly after, a conservative Christian arrives in Quahog and removes all the condoms from James Woods High, which causes the students to discover a clever workaround. Meanwhile, Stewie, fearing the Tooth Fairy, plots elaborate traps in an attempt to eliminate him.