Familiar Angel by Amy Lane

One hundred and forty years ago, Harry, Edward, and Francis met an angel, a demon, and a sorceress while escaping imprisonment and worse! They emerged with a new family—and shapeshifting powers beyond their wildest dreams.

Now Harry and his brothers use their sorcery to rescue those enslaved in human trafficking—but Harry’s not doing so well. Pining for Suriel the angel has driven Harry to take more and more risks until his family desperately asks Suriel for an intervention.

In order for Suriel to escape the bindings of heaven, he needs to be sure enough of his love to fight to be with Harry. Back when they first met, Harry was feral and angry, and didn’t know enough about love for Suriel to justify that risk. Can Suriel trust in Harry enough now to break his bonds of service for the boy who has loved his Familiar Angel for nearly a century and a half?