I just finished writing a love scene in the w-i-p and I'm ready to call it a day, because those scenes are far and away the most difficult ones for me to write. And here's why:
I don't write "sex" scenes. I write "love scenes" -- and yes, I think there's a difference. When my characters are making love, it's not simply a description of sexual activity. I'm showing two characters (and let me make that perfectly clear -- characters, not me and my husband) being as emotionally intimate as they are physically intimate. Their feelings are as exposed as their bodies.
Because such scenes are about emotional intimacy at least as much as physical intimacy, they're extremely important in terms of the developing relationship, which is the key element of any romance. So those scenes are key to the key. Hence, not something I can just toss off, like, say banter in a ballroom. (Note: Even banter gets revised when I'm writing it, but the first draft of that sort of thing is much faster to write than the first draft of a love scene.)
I also like to have dialogue in such scenes, but again, because of the importance of such a scene, it's not often the sort of dialogue that comes trippingly off the fingers the first time around.
I also don't want the prose to sound ridiculous, the sort of sentences and paragraphs those who would denegrate romance love to take out of context. I know it's out of context, but why provide any ammo?
I don't use anatomical terms for some parts of the human anatomy, but euphemisms. I know some readers think that's a cop-out and maybe it is. But that's what I'm most comfortable with; it's become a part of my style and I'm sticking with it. I do try to avoid the ridiculous here, though, as well.
Speaking of love scenes, I had an interesting experience with my latest release, HERS TO DESIRE. One reader wrote to say how much she enjoyed the fact that it was "tamer" than many romances when it came to the love scenes. Another reader wrote taking me severely to task for not enough "sex scenes."
My response is the same to both: the amount and intensity of the love scenes in any book of mine is determined by the setting (time and place), the plot and especially by the characters. Some characters are more physical than others, because of their backstory. Others are not. Some plots lend themselves to more sexual activity than others. For instance, if I've got two people in a marriage of convenience that happens near the start of the book, there will be more scenes of intimacy, because they're married. Bearing in mind that I write books set before the 20th century, if they're not married, they're probably not going to make love until much later in the book, and probably not as frequently. They don't have the pill, after all. I personally have a very difficult time with heroes and heroines in historical romances who just blithely fall into bed (or the carriage or the nearest haystack) with nary a thought that she might get pregnant and then what will they do? Obviously, since I have heroes and heroines who make love out of wedlock, I'm not saying that the H and H should never do that; I'm saying I think pre-marital sexual activity in a historical romance without any thought to the possible consequences bothers me.
One thing I don't worry about is what people will think. As in, say, my mother. I've been at this long enough to be waaaay over that. And after my Dad read the first one? No problem!
My daughter reads my books, but skips those parts because, EEEUUWW! I'm her Mom! Moms aren't supposed to know that stuff! She has no qualms about her friends reading them, though. I understand her school librarian was a bit taken aback by the sudden interest in THE VIKING, by Margaret Moore.
So while I'm not embarrassed to write love scenes, I do find them the most difficult to do well. And it's still all about the characters for me.