Yes i said SEX.
If you read romance, and i assume that you do, you know what you like to read and what you don't like to read - and again i'm assuming you don't like the porn version of sex scenes filled with all the dirty details.
You love Romance, which means sensuality in the sex scenes. You need to write more about the emotions and what is going on inside the characters head.
Here is a great post from the Mills and Boon website by Flo Nicoll last year for the New Voices comp, but no less relevant today! So, Let's Talk about Sex and remember the emotion, not the gritty details ;)