“A Thinking Person’s Guide to Autism” is a wonderful resource and online community. They have a blog, facebook page, and book so you can check them out in what ever way is most comfortable to you. Although they deal with many topics related to Autism Spectrum Disorders, they often touch on topics of sexuality.
I especially would recommend checking out this post, “Talking About Sex with Young Adults with Autism” Here’s an excerpt.
“Amy looked nice, but the grown-ups wouldn’t let us go in Amy’s room and shut the door.”
“Did Amy want to go in her room with you and shut the door?”
“Not really. So we went outside and the parents kept watching us.”
“Did Amy want to be alone with you outside?”
“I’m not sure.”
“Did you touch Amy?”
“I wanted to. I wanted her to lie down on the grass so we could do sex.”
“Have you ever had sex with anyone else?”