To hold your interest? And what about anticipation?
Over the years, when I used to have time for reading, I'll admit that I expected there to be sex somewhere in a story. I loved the anticipation leading up to the moment, and when the author delivered I was happy. But, those times the author closed the door and left it to my imagination I was so disappointed that I often put the book down and refused to finish it. All except for Kathleen E. Woodiwiss's books. Reading "The Wolf and the Dove" and "The Flame and the Flower" back in the early 70's, I didn't expect to read the explicit details between a man and a woman when they made love.
Now a days there's sex and plenty of it in romance novels. When I wrote "Cupid's Arrow" I wrote a lot of sexy situations between the characters that didn't deliver in the end. I felt that the anticipation of the big moment, when it finally came, would make up for the number of love scenes in the book. Quality over quantity.
Though it was my first book and is considered a sweet, traditional romance, it's probably one of my personal favorites. I really enjoyed building the relationship up between Mike and Emma. Feeling their sexual frustration and how they dealt with it, had me wanting to write more. I wanted to prolong their first time because I felt building up to it was just as important. And when they made love for the first time it was sensual, emotional and very fulfilling.
Do you expect there to be sex in a romance novel? Do you need for the hero and heroine to consummate their love for each other or are you okay with guessing what happens behind closed doors? My imagination isn't that good. I want to read the words.