The Alphas’ Exceptional Omega by Rebecca James

Angus Angel, a sixty-year-old alpha widow who was crippled in a ranch accident, finds a new lease on life when an omega named Ben arrives at Angel Ranch. Something about Ben makes Angus feel young again, and soon he’s ditched the wheelchair he’s been using in the past several years, and friends and neighbors are telling him he looks years younger.
Angus’ grandson, Maddox, believes that the partial bond Angus acccidentally formed with Ben on the night the omega arrived at their house somehow rejuvenated Angus. That’s all good and well, but Ben is much too young for Angus. Besides, he’s recently come to terms with the fact that his feelings for Colt, an alpha neighbor, go much deeper than he originally thought, although a relationship between two alphas won’t be easy.
Ben is an unregistered omega, and therefore a target of the government. Angus and Colt aren’t about to let them take Ben away, even if it means mating with the young omega.