Recently, I have gotten into a couple of alien series. they are both sci-fi but I do like the romantic interests in them.
Kristine Smith's Jani Kilian series. Not the most promiscuous hybrid alien around, but the men in her life are very interesting. I like romances that develope slowly. I took Anita Blake several books to jump JC and Jani is no different. Interesting characters and a paper trail mystery of murder, politics and drugs with a little bit of manipulative flirting on the side. Book two finally takes the romance a step further-- finally.
Wen Spencer's Ukiah Oregan series is wonderful. also a hybrid alien protagonist but a very fertile one- that seems to do more multiplying by division than by sex. Ukiah is a sweet young man who intrigues an older woman- FBI's Ice Queen. Their romance is a common denominator throughout the whole series.
Spencer's Tinker series has been mentioned here in reviews- an awesome book with a tender romance... I am awaiting the second one greatly....

AAJ