That you could get pregnant from it, of course!
Later on, I realized that it was a little more nuanced than that, but the main principle was still sound.
Ah. I'll share a story in exchange.
When I was in high school, I was very much a homebody. I'd go to school and do what I had to, but then I'd go home. School was the only place I would see my friends: I didn't visit them after school, on weekends, during vacations, not ever. When I went away to college, however, that changed. When visiting home, I'd look up my friends and we'd make plans to hang out and do stuff on the weekends. Our group of friends, of course, included girls.
Once, we made plans to go out to a pool bar, and they swung by my place to pick me up. One of the girls rang the bell and I needed a minute, so I invited her in (it was cold). So she walks in and says hello to my mom. Now, this girl was beautiful. She practiced ballet since the age of five, so she had a beautiful figure, walked gracefully, all around awesome. And she walks in wearing tight black leather pants and something that I hesitate to call a spaghetti strap tank top because it seemed to cover even less than what that would describe. She was very nice to my mom (and vice versa), but in keeping with her general personality, she was calling me sweetie and what not. All this made my mother rather uncomfortable, but she kept her peace.
About a week later, she asked to speak with me before going out with my friends agian. We sat down, and she started rambling on about the morals of youth in America and then she arrived at her main point: "If those girls offer you candy or something like that, don't eat it." It caught me off guard, and I didn't know what to make of it, so I asked her what she meant. Apparently, young people in America are full of raging hormones and like to use drugs and alcohol to enable their sexual promiscuity. I, being a good Christian boy, might innocently take the candy they offer, which may be laced with something, and find myself unable to resist a temptation that ought to be resisted. So I told her very plainly: "If those
girls have anything like that
in mind, I promise
you they won't need to offer me candy." Upon hearing this, she began to curse me in three languages.