Can anyone help me?

I stumbled across a really interesting word in one of Shigure's romance novels today. The word was orgasm. I didn't understand what it meant, and I know that Yuki is really smart so I asked him to explain it to me. He just turned really red and asked me where I'd seen it. I...kind of lied. I didn't mean to though! I just...didn't want to get into any trouble, or have anyone else think less of me. Shigure told me once that his books were too old for me so I should stay away from them. But I don't think they're too old because the publication date is really recent--only a couple of years back. And besides...I think he meant for me to read them after all, because he left this one (Stranger Encounters) propping open the door of his study when he knew I'd be cleaning that day. He later said his study had needed to be aired out. But I just think he wanted me to read his book and then tell him how good it was! Guys are so funny, sometimes. They don't want to admit that they want compliments, but they can't seem to live without them.

Anyway, I didn't mean to, but I sort of told a little fib to Yuki because I panicked. I just had this weird feeling...like, even though Shigure did want me to have it, I really wasn't supposed to. I can't explain it very well. But...I told Yuki that I saw the word in a magazine. Then he just smiled and told me not to worry about it, it wasn't important. He wouldn't say anything else when I persisted, just blushed even harder and asked me to fix him a snack if it wasn't too much bother.

I don't know why I can't leave it alone. Something about the description in the book that went along with the word fascinates me. It makes it seem important, although Yuki said it wasn't. I don't want it to seem like I don't trust Yuki, but something about his reaction made me think he just wasn't comfortable sharing his knowledge with me, and that's never happened before. Maybe Yuki thinks I'm too much of a baby to know about something like that. It is grown-up stuff I know, and something to do with how babies are made. I'm almost seventeen, though. Shouldn't I know more than that?

I looked it up on the internet, but only a list of web-sites containing some really embarrassing pictures came up, and I had to turn off the computer then. My eyes feel as though they're being burned out, except there's no pain.

Can anyone tell me what that word means?

I think I'll just ask Shigure tonight after dinner.