Single Dad¡Keegan x Logan except it's an AU where Logan owns his own business and is rich as hell, while Keegan's rotting in some one bedroom apartment after a bad divorce.
Keegan and Elias know each other from the military but are both retired, and one day Elias invites Keegan and his daughter over for dinner (yes he's a girl dad, her name's Ellie and she's four and a half, very important detail) and while he and Elias talk Logan casually plays dolls with Ellie and when the Keegan is driving home all she's talking about is how much fun she had playing dolls and ponies with Logan and how he said he had a horse at some fancy stables.
Elias invites them over again someday and Logan gifts Ellie some cool doll she wanted and Keegan is kind of bitter he couldn't gift something like that himself - especially when he hears Ellie say that he said they can't buy it now when she asked for it in the store. Logan gives Keegan a look, which the latter overthinks about for the rest of the dinner, but the next morning Keegan hears his doorbell ring, opens the door and all he finds is a bag full of groceries and some dolls and ponies for Ellie. With a note saying "call me if you need help with anything" and a phone number.