Manicurist!Castiel who works in an upscale men's spa. Dean Smith always comes in on the weekend for a massage and to spend time in the steam room, but he also books an hour with Castiel.
Castiel buffs and clips his nails, massages Dean's hand and makes small talk with him about the state of the world. Dean Smith tips extravagantly and Castiel thinks he'd always like to ask for more, but that's not the sort of establishment they are.
When Castiel is off sick one week, Dean cancels his appointment because, as he tells the receptionist over the phone, he only wants Castiel to touch him.
Castiel can't help feeling pleased when he hears that and the next time Dean comes in, Castiel works up the courage to flirt with him. Dean ends up staying until closing time, doing laps in the pool, until Castiel finishes for day.
He takes Castiel out for dinner and it's the start of something beautiful.