Slave World Book 1 by Kelex
One of the last humans left after the Takaerie destroyed Earth, Thomas lives on Mythria and works the mine there to earn a meager living. He meets the daughter of the mine’s owner and falls head over heels.
When her father catches them in the act, he becomes enraged and demands satisfaction for Thomas stealing her innocence. On trial, Thomas is charged and sentenced to be auctioned off to the highest bidder on Valkin, a sex slave planet.
Once on Valkin, Thomas stands on the block and faces the new world with as much pride as he can muster, which attracts the attention of Lord Valyr, who has always coveted a human slave.
Forced into the possession of a master, Thomas fights the dark desires being a submissive cause within him, without much luck.