The Coil by LA Gilbert MM

Sandwich-maker Mattie Green has one goal: escape San Diego, move to New York, and attend art school. But to make this a reality, he needs to get his GED—not easy, since he can’t read or write. Until he can, he’s stuck working at the diner and selling himself on the side.

Mattie’s legitimate job isn’t without perks. Every day the quiet, sophisticated Simon Castle comes by to work on his latest book. Mattie wants more than to pour Simon’s coffee and make his lunch, but he’s sure Simon is out of his league—until suddenly he’s not.

Simon Castle's life is complicated, built around his career and a son who requires a lot of time and attention. It’s not a life well-suited to the inclusion of even a part-time prostitute, so he resolves to keep his relationship with Mattie casual. However, the longer he knows Mattie, the deeper his feelings become. The idea of him with another man tortures Simon, but he can't ask Mattie to be his alone and jeopardize Mattie's hopes for New York—no matter how much he wants Mattie to stay