Sexting Teacher examines three cases of teachers who formed illegal relationships with underage pupils, exploring how mobile phones and social media facilitated their actions. Through dramatic reconstructions, police interviews and court evidence, the documentary investigates the case of Jeremy Forrest, who fled to France with his 15-year-old pupil, alongside two other cases that resulted in criminal convictions. The film explores the devastating consequences for those involved and the dangers of teachers exploiting their positions of trust.