Well, why not?
I began my writing career pretty much writing whatever I wanted. My first manuscript was about the romance between an injured football player and his physical therapist, written back when sports heroes were anathema to publishers. The sex was racy and the acts clearly stated without any throbbing members or heaving bosoms, but less frequent than most current steamy offerings. Walk Like A Man has always been popular, and will be available in a couple of weeks as part of an anthology, Falling in Love.
My three subsequent manuscripts were in the same vein, with sex included as a part of a normal relationship.
Then I was signed to Silhouette Romance, where rules concerning sex were strict. No sex without marriage and I had to be careful about how that sex was described. Still, I got away with a lot because I got the characters married at the midpoint of the book, and by the fourth and last book I wrote for SilRom the sex was fairly graphic. No cocks and cunts, but female cores and male rods joining--that sort of thing.
Then SilRom folded and I was orphaned, but free to write what I wanted. I didn't know quite what to do with myself, and when a couple of friends confessed that they'd been doing well writing for the online erotica market, I thought, "Why not?"
So I sexed up an otherwise fairly staid holiday story and sold it to Ellora's Cave, then a leading purveyor of online erotic romance. While EC didn't buy everything I wrote, there were a plethora of other online erotic romance publishers who took what EC didn't like.
However, the difficulty I faced was the other side of the coin from Silhouette Romance. Rather than avoid sex, I had to shoehorn it in constantly to satisfy the appetites of either my readers or my editors--couldn't figure out which and it really didn't matter.
I found a variety of ways to do this given that I don't like to confuse heroine and ho. In my books sex occurs in the course of a naturally unfolding relationship, just like it does in most people's lives (including mine) unless they're randy teens figuring out how to do it or twenty-nothing males with weak egos, seeking to scratch another notch onto their bedpost to compensate for some other failing.
The easiest technique is to start a story in the midst of a relationship, as I did
with Gypsy Witch. Here's the first paragraph:
Ben propped himself up on his elbows to better see the naked woman beneath him. Sheened with sweat, Elena’s lush curves glowed in the reddish half-light of her bedroom, curtained in exotically patterned swaths of gauze and silk. A curl of smoke from a lit incense stick scented the air with sandalwood. Otherworldly New Age music flowed out of a boombox in the corner, irritating the hell out of him.
This is one of the better first paragraphs I've written. Not only does the story start with a bang, but there's a fair amount of characterization and conflict indicated. Setting is described as well.
Erotica is a great thing. Hey--there's a need for stroke books. However, as an author, I really do prefer to write romance that includes erotic content rather than erotica. Erotica is just less satisfying to me in terms of writing craft. There's something unnatural about a story that's just sex sex sex sex sex sex. Unless you're a prostitute, our lives are more full and varied. It's more interesting to write about a variety of human experiences rather than just one.