Distinctly Daray by Jessamyn Kingley

Victor Antonov-Daray is a lucky man. Thanks to his impetuous decision to apply for a job he didn’t qualify for, his life changed forever. In the decades since, Victor has gained experience, poise, and a found family. The Darays anchor his world.

Every twelve months, new fallen knights are resurrected. Keegan Hayes considers himself fortunate to be among them. As a recruit, he is eager to train and study. Shortly after classes begin, Keegan discovers there is a shifter sentinel struggling to adjust to his resurrection. Keegan insists on meeting him.
No sentinel likes to stick out, but Phillip Osdraconis has no choice. His dragon will not allow him to rest. It takes sorcery to force the beast into submission. His precarious start means he is not ready for the courses necessary to prepare him for his future duties.

Phillip refuses to accept his fate idly. He is determined to forge a bond with his dragon, read his textbooks, and spar with his brethren. To his surprise, visitors arrive at his dorm door to greet him. One of them is his mate, Keegan.
Although they are pleased to be paired, their relationship is awkward. That is, until Phillip and Keegan are invited to dine with the Darays and they meet the missing part of their soul, Victor.

Now the three men must navigate the perilous road of a triple matebond. They do it willingly and with complete determination. Victor, Keegan, and Phillip soon learn everything is easier with love.