Obsession by Jason Collins

JOSH:

My love life is on the backburner—or so I thought. I moved to this small town to escape my overbearing ex, and I became a rent-a-spouse to pay the bills. But I didn’t plan for Keaton, my ridiculously handsome new boss.
I’ll be Mr. Thornhill’s husband any day of the week.
Keaton’s attracted to me, too, and he wants a real relationship. Our chemistry is too strong to ignore and being in his arms makes me feel safe again. But when my ex reappears and won’t stop harassing me, I’m tempted to run. Except that would mean leaving Keaton behind.

KEATON:

It all started when my new rent-a-spouse walked through the door. Josh is charmingly soft-spoken, witty, and full of mystery. I needed someone to cook, clean, and make the house a little less lonely in this mountain town. Instead, my new “husband” has the physique of an underwear model.
I’m not complaining.
Around Josh, I’m happier than I’ve ever been. He’s addictive, and our relationship becomes more than just a contract. But Josh carries a sadness in his eyes I can’t explain, and he refuses to talk about his past. If he won’t let me in, I can’t protect him from the ghosts that still haunt him.

This is the second book in the Rent A Spouse series. It can be read as a standalone with no cliffhanger.