They were both hungry, and tired, and so when Hermione returned from her foraging trip, a look of delight upon her face and a Sainsbury's bag in her hand, Harry thought he could kiss her. He wouldn't though, because while winding Ron up was funny, somehow he didn't think that would go down well.
"I couldn't take it anymore!" she said. "I thought: there can't be Death Eaters waiting for us in every supermarket." She shuffled guiltily. "And I really wanted a Coca Cola."
"What's that?" Ron mumbled around a slice of bread, covered liberally with butter. Harry and Hermione exchanged a glance as she pulled the rest of the groceries out. Potatoes, cheese, apples, chocolate, (oh Merlin chocolate!) and various tinned foods. Finally, she withdrew three bottles of coke with a flourish.
"Do you know how many spoonsful of sugar there are in one of these?" Harry teased, sliding a bottle toward himself. She swatted him on the arm.
"We're all allowed our vices," she replied primly. He grinned.
"Looks kind of gross," Ron said, eying the bottle warily. Harry thought of how disgustingly luminescent pumpkin juice was, and said nothing. Ron shook the bottle, and Harry stifled a laugh. Hermione opened her mouth to say something, then clamped it shut, an evil twinkle in her eye.
WHOOSH! Ron opened the bottle, and it exploded everywhere. Harry and Hermione had tactically shuffled back, and so just Ron and the surrounding foliage were covering in the fizzing liquid.
"What the buggering fuck!" Ron yelled, holding the bottle at arm's length. Harry gave in and began to cackle.
"You! You knew this was going to happen!" Ron said, pointing an accusing finger at him, then glaring at Hermione. "You too!" Hermione stifled a giggle behind her hand.
"Try it," Harry urged him, gesturing to the half empty bottle. Ron gave him an incredulous look.
"It just exploded! And you want me to put it in my mouth?" Harry grinned, opened his own bottle, and took a swig, sighing in delight as the cola fizzed on his tongue, and made him shiver.
"Wimp," Hermione said. Ron's eyes narrowed, and he drank a mouthful. He spluttered.
"It fizzed!" he cried. Harry chuckled.
"It's supposed to. It's a fizzy drink." Ron stared at the bottle, and took another sip.
"I suppose it's quite nice," he said reluctantly. He re-joined them, apparently unbothered by the state of his sticky clothing. "Muggles," Harry heard him mutter to himself. "Exploding drinks. What next? Exploding boxes?"
Harry decided not to get into the details of what a bomb was, not today.