Surprised Daddy by Liam Kingsley

Shawn is devastated after learning he is unable to carry children of his own, and he knows that no alpha will take a chance on a barren omega. After all, his last alpha left him when he was unable to conceive. Ever since then, Shawn has struggled with fears of abandonment. As he gets closer to Linc he finds himself wishing he could give the sweet alpha everything; his body, his heart, and more children to love.
Linc loves being a dad to his eight year old son, but inside he yearns for more. Discovering Shawn is his fated mate is a dream come true but it will take time for Linc to convince his stubborn, heart-scarred mate that they have a future together. With the support of his pack, Linc and his inner wolfdedicate themselves to to wooing the skittish omega. And when a surprising revelation binds them even closer together, he’ll prove that he’s just the man to love Shawn… forever.