Lethal Impact by Viola Grace

Living as human prey beneath the earth, Fiona knew that anything would be better than the life that stretched ahead. The stars made an offer and she took it.
Used as a sexual trading card between the rich and powerful survivors of the lethal impact has left Fiona with an urge for change. She needs out and the offer from an alien race to be a bondservant until she paid out her transport and training is an offer she wants to take them up on.
Once on the education base she gets the help she needs to feel something again, and that training is going to come in useful when her test results come back and place her in an elite group of humans who can be of use to the Hmrain.

Aarak has just learned about the humans from his sibling, and as he was in the area, he decided to see if another human could be found with the high sensuality rating that his people needed to feed. He wasn’t thinking of his people, he was thinking of securing a long-term bond mate that would serve him as he needed it. He could never have anticipated the wounded woman with the heart of gold who brought up instincts he never knew he had.