Broken Ponies by Charity Parkerson

There was a time when Buck planned to marry Sterling. Sterling shattered everything. He doesn’t have any chances left to give.
Sterling grew up on a ranch. Horses are his everything now. As a professional polo player, he has his dream career. But it’s starting to feel like a nightmare, closing in on him. He thinks maybe it’s time to go home. Unfortunately, home is where his heart is, and he can’t take back the way he left things with Buck. It’s a hard choice between facing Buck again or facing his upturned life by going back to work. Both options leave him equally doomed.
Buck has worked the ranch for over a decade. He watched Sterling turn into an amazing horseman. Buck also fell in love so hard it knocked the good sense from him. He knew to the bottom of his soul he would spend his life with Sterling. That is, until Sterling wrecked everything good about them. Now Sterling is back, and the feelings are still there, especially the hatred. Buck is pretty sure loving Sterling again will kill him.