In His Corner by Kerri Duffy

A grumpy gym owner. A man with nowhere left to run. And a couch that was only supposed to be temporary.

Tiernan O’Rourke has built his gym into a safe space for queer fighters. Something he never had. But when Arlo walks through his door with nothing but desperation and a borrowed pen, Tiernan decides safety shouldn’t have a weight class.
Arlo has survived on one rule — trust nobody. Tiernan O’Rourke didn’t get the memo. He keeps showing up, keeps being steady, keeps being the one exception Arlo has no defense against.
Tiernan never expected to fall for Arlo. Arlo never expected to belong anywhere. Together, they just might find what they’ve both been missing.