My First Promise (Blue Sky Bay, 3) by Laura Pavlov

He doesn’t do relationships. But for her, he’ll play husband.

Phoenix Stark does not do relationships. Nor does he make promises. And he definitely doesn’t believe in happily ever after. He’s a broody tattooed firefighter and a man of very few words. Except with me.
When my five-year-old nephew is unexpectedly left in my care, I'm determined to give him the stable home he deserves. But between my part-time job and his Type 1 diabetes, I need more than love to make that happen. I need health insurance, a home, and a husband.

Phoenix offers me all three. His solution? Marry him.

A fake marriage to my oldest friend should be simple, except suddenly I'm living in his house, sharing his bed, and convincing everyone around us that we're madly in love. And somewhere between raising a little boy together and pretending that this marriage is real, the lines we've spent a lifetime protecting begin to disappear.

But Phoenix doesn't believe in forever. And I refuse to risk the best friendship I've ever had for a love he may never be able to give me. The problem is, I'm starting to wonder if the man who refuses to promise me forever has been loving me all along.