Resident Billionaire by Cheryl Phipps

What if you had to choose between loyalty and love?

Caris Knight has fallen in love with the cowboy. It can’t work—there’s too much opposition, with the tall fair-haired Texan being the biggest obstacle of all. But Caris is used to obstacles, and she’s not made for giving up.
Andy loves the Knights. When he was orphaned they saved him in too many ways to count. After a stint in the army he came home to see that the baby of the family was all grown up, and the mutual dislike had morphed into something he can’t deal with. She’s his best friends’ sister which makes it wrong. Doesn’t it?