Red Hot by Sean Ashcroft

“Red Hot? That’s the profile title we’re going with?”
Newly-out firefighter Red has a pretty average life—a job he loves, supportive friends, big dreams, and a little trouble finding a roommate. That is, until he rescues a slightly odd computer nerd from his burning apartment building.

Andy isn’t just any computer nerd. He’s the computer nerd who single-handedly built the up-and-coming dating app, M4M. Until now, Red’s been afraid to put himself out there—but with Andy as his new roommate, he’s not going to have any choice. Andy needs a test case, someone to prove his matching algorithms can find anyone the perfect partner.

When he discovers that Red’s never been on a date before, Andy makes him his pet project—he’s going to find Red the man of his dreams, whatever it takes.
The only problem is that Andy is the man of Red’s dreams, and Red can’t bring himself to face the embarrassment of telling him—after all, Andy isn’t interested, right?
Little does Red know that Andy’s been thinking the same thing. If only his algorithms agreed…