They spend so much time together and clearly have the hots for each other. Tiernan even loses her virginity to Jake and they sleep with e/o for a while. There are even chapters in Jake's POV.

Does Caleb ever talk in credence?

There's no deeper reason. They never speak to each other, Kaleb isn't even in like half the book, he rapes her like it's going out of fashion… even when we get a chapter from his perspective, it's evident he feels nothing for the heroine besides a vague physical interest in her.

Is credence a stand alone?

*Credence is a full length, stand-alone romance suitable for readers 18+.