Watermelon
Remus at last relented to the boy’s begging, handing little Harry the box filled with watermelon slices.
“But be careful, don’t get your things dirty,” he said, despite knowing it was probably hopeless anyway.
At least if the boy had his snacks now, it meant Remus could focus on gathering the rest of their things for the trip back home. They had to be at the station in twenty minutes, and he did not want to be two hours into a train ride to Wales when he remembered he’d forgotten something important like his wallet or Harry’s favorite teddy in London.
His ruffling through the bag was accompanied by the loud crunching and smacking of a watermelon being eaten, and the happy giggling that always came from Harry whenever Padfoot was around.
Being sure they had thought of everything, he turned back around, only to be witness to the dog taking a big bite from a half-eaten slice of watermelon from the boy’s hand, crunch his way through it, juice tripping out of his mouth (probably more landing on the floor than in his stomach), and then sloppily lick Harry’s face.
The little boy was obviously delighted by Padfoot’s shenanigans as always, giggling almost hysterically.
By the state of them both, that’s what had been happening the whole time Remus had been a responsible adult and guardian. Harry’s face, hair and clothes were smeared with juice and slobber, and Padfoot’s fur looked no better, his whole head and neck visibly wet.
“Padfoot,” he warned, and the dog at once stopped licking the little boy’s face to look at Remus with attentive ears and big, innocent eyes. The dog licked his lips, gathering up some of the juice still dripping from his muzzle, and swallowed, so painfully obviously guilty of his crimes.
Remus was about give him a stern lecture, he really was, but then he just sighed, defeated.
It was already too late anyway.
Nothing else to do but wipe them clean so they looked at least half-presentable and hope for the best.
A dirty child was a happy child, or whatever it was they said.