Sex Ed is high school

So my sister came home from school telling me about how they had a speaker at school teaching about std's and getting pregnant. And I'm like great! What did you learn? Apparently the speaker was telling the kids that if you masturbate or watch porn while in a relationship you're more likely to cheat, I think that is BS! Also the speaker went on saying if a girl dresses proactively she is asking to be raped. I'm livid at what they are teaching! So my question is should Sex Ed speakers come to school if they're going to be talking this nonsense?