Scorching for His Omega by Harper B. Cole

The strongest superpower is love.
During the day, Alpha Blaze Wayne saves lives as a doctor at the local hospital. At night, he saves the world as Doctor Fire, along with the rest of the superheroes known as the Defenders.
Yet there’s one thing he’s missing: his elemental omega. As a human that negates his fiery powers, his elemental omega is the only person he can hope to have a happy future with.
That is, if he can ever find him.
Omega Vincent Edwards has lived a sheltered life as a computer programmer, but it isn’t until he witnesses Doctor Fire fight against a monster that he feels the spark of adventure. And when a doctor at the hospital tells him that they’re fated to be together, he realizes that he may have found his mate.
There’s only one person who can stop them: The evil supervillain Aquaphobius who will stop at nothing to destroy Doctor Fire’s happiness. And with a baby on the way, Blaze and Vincent will do everything they can to save their futures.