Franklin by Catherine Lievens

Some bonds can’t be ignored.

Franklin has one mission—finding his siblings. He knows the Glass Research Company has them, but he doesn’t know which facility they’re in. Working for the company hasn’t helped him so far, but maybe working with the mutants will.
Reed escaped the facility where he was held captive six months ago. He carries the guilt of having worked there as a lab technician before an accident turned him into a mutant, and he’s been trying to atone for that. When he finds out that Garrett, a man he grew close to while in the facility, is about to be auctioned off, he reaches out to the mutants for help.
When Franklin realizes that the man who’d just admitted to working at the facility where his brother is kept is his mate, he can’t accept it. He doesn’t have the option of not working with Reed, though, not if he wants to save Garrett.

The bond between mates is strong, even when they shouldn’t want each other, but Franklin’s priority has to be his siblings. That doesn’t mean there’s no place for Reed in his life, but can he get over Reed’s past?