Boys vs. Girls
Boys: "Use a condom. You don't know if she's on the pill or really a slut. But I need to meet this girl first before you stick your dick in them. Its a boy? You bottom? Well, make sure they use a condom still. STDs are disgusting."
Girls: "Don't even think about it. It costs money to have sex for us women. Condoms, birth control... Money. And them when you do lose it-- doctors visits to make sure you're clean. Pap smears. OB/GYN. Its big business when girls have sex. Now, if you're gay, that's slightly different. Just don't do anything you know you'll regret later."
Both: "Stay safe. It's a big world out there and, although it might be fun and games at first, it can result in serious issues that you may deal with later. I love you. Talk to me any time you have more questions."