Bring a favorite novel to bed with you, preferably one with a hot sex scene or two. Bookmark a racy passage and then read it out loud to your boyfriend using your sexy voice. Or the two of you could take turns reading. After you've read a few pages you could reenact the sex scene with a few of your favorite moves thrown in. It can feel funny at first, but remember that being silly and having fun are great ways to get things cooking.