Turn Left for Stars by V. K. Ludwig

It’s hard to find the right alien concubine…
Finding three of them? Impossible! Watching the future saikhs practice their penetration angles at the saikhmenti alone doesn’t cut it to make a decision. What about other things like… I don’t know. Personality?
What I need is insider information.
That saikh-in-training who keeps failing his assessments? He’s offering it up freely. Kinda. All he wants is practice those fancy skills on me, or otherwise he might flunk his finals.
Meh, why not?
Don’t accuse me of caring. All I do is let him improve his skills in exchange for dirt on his classmates. I’m technically a martyr, taking one for team Earth here. You’re welcome.
Besides, how bad can he be?
Turns out, not bad at all.
In fact, he’s so good I can’t help but wonder: why do I need three saikhs if this one pleases me so perfectly?
(Wait, I just remembered why! Because I signed a contract stating I would do exactly that. Well… eff me.)