FIRE on Fire by Lukas Gaines

Ash is trying to retire early.
Kael’s just trying to pay rent.

Ash Pierce lives by FIRE: Financial Independence, Retire Early. He has a spreadsheet for his money, his workouts, and the freedom date when all his deprivation is supposed to become a life.
Kael Wright has paint on his jeans, overdue bills, and a billionaire patron whose generosity feels more like a leash. Worse, that patron is Alistair Blackwood, founder of tech giant Query, where Ash’s recent demotion has knocked years off his carefully plotted future.

When Ash trips over Kael at a mountain retreat, sparks fly before either of them knows better. Ash sees a walking financial emergency. Kael sees a spreadsheet in tech bro form. By the time a wildfire strands them in the Northern California backcountry, they’re both certain the other is a complication they don’t need.
Too bad the mountain keeps forcing them to trust each other, through smoke-choked trails, desperate shelter, and every mile between them and safety.

All that friction was bound to slow-burn into something neither of them planned.
But holding on to each other means facing everything waiting off the mountain, including the billionaire with far too much control over both their lives.