Who I Became With You by N.M. Frank

Luke
Luke never planned to become a protector. But after a tragedy shattered his world, he vowed no one within his reach would suffer the same loss. He now works as a personal protection officer with a private security firm, dedicating his life to keeping others safe.
One night at the nightclub his firm is contracted with, he encounters Oliver. A quiet, guarded, man with eyes steeped in sadness and pain. Luke suspects Oliver is in trouble and gives him his card, expecting him to disappear into silence.
Three weeks later, Oliver calls.
Offering him a safe place to stay is supposed to be temporary, just long enough for Oliver to catch his breath and decide what he wants to do next. Instead, days stretch into months, and what begins as a fragile arrangement built on safety and trust deepens into something Luke never expected and can’t bring himself to walk away from.

Oliver
Oliver thought escaping his abusive father was the worst thing he’d survive.
He was wrong.
The man he believed had saved him became another captor, leaving Oliver trapped once more.
Until Luke.
The towering man, full of muscle, looks like everything Oliver has learned to fear but offers a gentleness he’s never known.
As Oliver slowly reclaims the pieces of himself that were stolen, he dares to imagine what he thought he’d lost forever: safety, choice, and the possibility of being loved simply for who he is.
Over time, he falls for Luke. There’s just one problem. Luke is straight and on the ace spectrum. There’s no way he could ever want Oliver . . .
Right?