From Hell, With Love - Bryce Oakley

Ramona Greenbriar did not mean to summon a demon.

Divorced, academically disgraced, and working retail at a fake magic shop - she has enough complications. Her magic has never once done what it was supposed to, which is probably how the demon got in. That, and the grimoire came out of a donation box alongside a moldy sandwich. It was always going to go badly.

Enter Azareth - three hundred years old, impeccably suited, and going absolutely nowhere until the next new moon, whether either of them likes it or not.

Which means explaining to her roommates why there's definitely-not-a-demon in the apartment, trying not to notice that Zara is extremely hot, pays attention like it costs her nothing, and treats Ramona like she's someone worth the trouble.

Falling for a demon wasn't the plan. But then again, nothing in Ramona's life has ever gone to plan. Why start now?