sex ed question

okay folks, i'm going to draw on your expertise.

how would you convince someone to use condoms?

specifically, how would you convince a sexually active 15 year old who thinks it's okay because they're on depo so they won't get pregnant?

the thing is, when i was in high school AIDS was still a really big deal in the media and in sex ed classes and so on, so the idea of unprotected sex basically never occured to me. which means, i have no idea what is needed to convince someone otherwise.

you know how there are people that preach abstinance until marriage? well, i think instead of that people should preach protection until a marriage-like union. which makes me a raging lefty, i know this, but it just seems logical to me, because really, abstinance? seriously people, as if that's going to happen.

so, coming from the woman who was so preganant paranoid that she was on the pill AND used condoms until about a year ago (i've been with john for over 12 years, you do the math...), i need to know how to make an argument for condoms that will be convincing to a 15 year old.

any resources, words, advice, wisedom, anything you can share on the subject would be appreciated.