Chilo Ketlhoafetse struts around an eighth-grade classroom like the coolest guy in Botswana, warming the students up to talk about an awkward subject. He calls out "Nomhlaba!" and they respond "Auwe!" — nonsense words from a local childhood game. Soon he has the students clicking their fingers, dancing and following his every word.
Within an hour, the students at the Bakgatle Community Junior Secondary School in Mochudi are chanting the only message he wants to get across to them: "Older partners are riskier."