There seems to be a huge misunderstanding concerning what consent is when it comes to sex. And yet -- when discussed with teenagers -- the idea that "unless someone says 'yes', it's not consent," is easily accepted. It's not a hard conversation: Unless you get a "Yes," assume "No." Uncomfortable, maybe, but difficult? Hardly.
Please make the line between a clear "Yes" and anything else -- whether it be someone drunk, asleep, or otherwise unable to say "No" -- something schools must cover in health or sex ed.
If STI information and methods of contraception are standard fare, consent should be, too.