I haven't seen any other fanfics for this film yet, so I suppose this is the first?
Disclaimer: The film Papadopoulos & Sons is not mine - I am incapable of such excellence - so I'm not claiming any kind of ownership.
SPOILERS if you haven't seen the film yet.

Mehmet had come to pick Katie up again, to find Harry manning the shop alone. It was Sunday night, late enough for most of his customers to have come and gone – he never could convince people that they didn't close early on Sundays – so he'd given James the night off and watched him head out the door towards the pub with a big grin on his face.

Mehmet hovered awkwardly in the doorway, as he always, did, until Harry beckoned him forwards. He took a seat at one of their little tables and gestured for the boy to take the other.
"Katie's running a bit late, she'll probably be at least ten minutes or so." Mehmet bobbed his head in understanding and took his seat. "How's Hassan?" The boy smiled; apparently he'd been expecting a more difficult question.
"Yeah, he's good, thanks, yeah."

Harry glanced towards the stairs; this was probably the best chance he'd get to have a word with Mehmet about his daughter, and he didn't want her walking in on it.
"Listen, Mehmet, I don't want to sound like an overbearing father, but I want to know. What are your intentions towards Katie?" The boy looked confused for a moment before answering.
"Well there's that new restaurant round the corner's just opened, looks dead nice, really fancy, so we're going in there on the way to the cinema-"
"That's not what I meant." Mehmet's expression turned bewildered and somehow apologetic.
"Then what did you mean?"

Harry thought about it for a moment; what did that question even mean? He gave up.
"I just want to know - this thing between you two, is it serious or are you just messing her about?" Mehmet frowned again, face open and honest as it always was.
"Of course not, I'd never mess Katie about. She's too amazing, she's really special." The mere thought of her had put a warm smile on his face by the time he'd finished speaking; Harry believed him.
"Good."

To his surprise, Mehmet looked more worried by his acceptance than he had before. He didn't have to wait long to find out why.
"Are you going to say that if I really love her, I'll let her find someone better?" Harry considered it, briefly, but Mrs P was right; Katie was eighteen and could make her own choices.
"No. Why would I say that? Who said I'd say that?" The boy's eyes widened.

"No one! I just thought, cos... in films..." Harry burst out laughing.
"Maybe you should stop letting my daughter choose what you watch."

There came a clattering of heels from the stairs and Mehmet leapt to his feet as Katie flew into the room and handed him her handbag so she could shrug a jacket on.

"You'd better not have been mean to him, Daddy." He raised an eyebrow.
"Nice to know what you think of me. Is that flower in your hair one of James'? From the roof?"
"Don't tell him, please. Night Dad, don't wait up!" She was already dragging her boyfriend towards the door.
"Night, Mr Papadopoulos." He raised a hand in farewell.
"You kids have fun." He ignored Katie's shocked expression as the door shut behind them, watching their cheerful progress down the high street for a while before heading back behind the counter.

Maybe Mehmetwas good for Katie after all. He clearly loved her. And maybe a guy who thought Pizza Hut was a fancy restaurant and believed in all the cliches in the trashy rom-coms Katie loved was just what his daughter needed. They made each other happy, and that was enough for Harry.