Trick or treat! Wincestiel + master!cas and pup!winchesters. The boys get into the Halloween candy meant for kids on Halloween night? :)
Castiel has to work on Halloween, but the boys don't. They have the day off, and get to stay home. They're supposed to wait for Cas to come home, have dinner with him, and then they'll all hand out candy together in the evening.
They don't exactly follow the plan.
When Cas does come home, his pups aren't waiting at the door as they usually are. "Boys?" He frowns, growing concern as he hears no sounds of rowdy puppy play that might have distracted them from his homecoming.
When he gets into the living room though, he understands. The large bag of candy he'd bought for the kids is sitting on the table, empty, wrappers scattered around it. The pups are splayed out across the floor, groaning, hands on their bellies.
"You ate it all?" Castiel is a bit shocked, that means forty pieces of candy each if they split it evenly. A whine answers him, Dean raising his head from the floor slightly. "At least it was its own punishment." Cas sighs, walking over to sit beside his pups and rub their swollen bellies. "Did you eat lunch?" They shake their heads, looking properly ashamed. "Naughty puppies, now you've gotten yourselves sick and we have nothing to give the children!"
The boys groan in response, and Cas tells them to stay put, as if they can move. He goes and buys more candy, bringing it home and then getting them to eat some rice and chicken for dinner once their stomachs settle some. At least now they'll know better than to overdose on sweets, especially since they're not allowed on the bed that night.