How much is too much...
This may not be controversial everywhere, but it is where I live.
I personally am a fan of teaching middle and high school students the facts. Not saying "hey go out and have sex if you want" but teaching how to have safe sex and avoid pregnancies and STDs. And that a lot of STDs can be asymptomatic and that they can be transferred through oral or anal as well.
Instead, what my area has is one year that pregnancy and STD prevention is discussed. The whole curriculum is 8 years long and covers things like healthy families and friendships (which I totally support) multiple years, but there is literally only ONE YEAR that pregnancy prevention can be discussed.
And, I actually work in a position that I could start the discussion on a more comprehensive sex Ed program, but that's a battle I'm not willing to fight just yet. So I'm working on teen dating violence instead.