Bull Moon Rising (Royal Artifactual Guild) by Ruby Dixon

In a world of magical artifacts and fantastical beings, a woman determined to save her family joins forces with an unlikely partner—a minotaur—in this steamy romantasy by USA Today bestselling author Ruby Dixon.
 
As a Holder’s daughter, Aspeth Honori knows the importance of magical artifacts . . . which is why it’s a disaster that her father has gambled all theirs away. Now that her family is in danger of losing their hold—and their heads—if anyone finds out the truth, Aspeth decides to do something about it. She’ll join the Royal Artifactual Guild and the adventurers who explore ancient underground ruins to retrieve the coveted arcane items.
 
It’s a great plan—with one big problem. The guild won’t let her train because she’s a woman. Aspeth needs a chaperone of some kind. The best way to get around this problem? Marry someone who will let her become an apprentice. Who better than a surly guild member who requires a favor of his own? He’s a minotaur (it’s fine) who is her teacher (also fine) . . . and he’s about to go into rut (which is where it gets tricky). He also has no idea she’s a noble (oops), and he’ll want nothing to do with her if he discovers her real identity.
 
Now Aspeth just has to pass the guild tests, thwart a fortune hunter, and save her hold—oh, and survive a rut with her monstrous, horned husband, whom she might be falling in love with.
 
It’s time to dig deep. Literally.