When I was 13, our science teacher told us to be mature when talking about sex. She said 'Come on, guys. We're going to be talking about penises and vaginas' and I was the only one who giggled and the teacher angrily said about me 'and someone should NOT be laughing!'
Which I found hypocritical because another time she was giggling when telling us that boys shouldn't take particularly hot baths as it damages sperm count :/
ok thanks for that info actually