My wife has some reproductive problems, which have caused her a lot of trouble and a total of 5 surgeries. Because sex, at times, was painful for her, and because I wanted to learn about her illness, we've developed a very easy back and forth about sex. I've also found that as I undertand more of the anatomical/biological aspects of the female reproductive system, any embarassment I might have talking about it goes out the window. I go with the wife to the OB-Gyn, and while I'm not present for the examinations (which should be between the doc, nurses, and patient), I am invited to the consulations -- my wife says the moral support does a lot for her.
On a somewhat unrelated note, I remember one time, my wife was feeling rather ill during her period, and needed some pads. She can't use tampons, so there's this specific type that she always uses -- but she wasn't up to driving to the store to get them. No biggie, I went for her. So I walk to feminine hygiene aisle, locate and grab what I need, when I see this gentleman looking very nervous and lost. Obviously, he's there for the same reason I am, but he's not too sure what to get. I guess I looked friendly or something, because he came up and said, "Um, I'm a little embarassed, but could you help me out here? My wife's on her period and she sent me here to get her something. Will these do?" And he holds out this little package of teeny tiny panty liners. Supressing a laugh, I said, "Uh, no those aren't going to cut it," and pointed him to some larger, more absorbent models.
The point being, men who are embarassed about sex are probably just ignorant and too scared to ask their partner questions. I've found that women normally have no problem filling a guy in on anything they want to know in a gentle and not to overwhelming way.
Imma rate this article *insightful* because you've certainly made ME think about it more!