Balor by Elle Harper

Isabella is used to running. She spent years trying to get away from her former love, and finally, it ended up that getting stranded a few galaxies away ended up working like a charm. She swore that despite how pretty it looks from the outside, she’d never let herself get involved with anyone again. She’d thought she had heaven once, and it had turned into hell. Clearly, her judgment when it comes to the male species is more than a little suspect.
And a womanizing, bed-hopping, cocky alien pilot is exactly the last thing she needs. No matter how intensely Balor looks at her, how smooth his voice is, how much he makes her fantasize about doing filthy, mind-numbing things with him. Getting caught up in the fantasy of him would only end up hurting her. Been there, done that.

Balor
Losing those you love is part of Izothian life, thanks to their millennia-old war with their enemy, the Sa’tar. And Balor has lost enough: his mother, his father… even the female he’d vowed to take as his mate. Connections only hurt in the end, and the fewer of those you have, the better.
So why can’t he get the sweet, brilliant, soft-spoken little Earthen out of his head? And why does she have him wanting to do crazy things… like beg her to be his forever?