Sighing, you roll your eyes and wind your arm back. "Ugh, whatever you say, boss..." and with all your might, deliver a firm fist straight into Naruto's muscular stomach. Almost directly upon impact, a rush of air forced its' way directly out of the boy's mouth and right into your face, as you feared but predicted.
*BBBBBBBBBBBBBBBBBBUUUUUUUUUUUUUUUUUUUUUURRRRRRRRRRRRRRRRRRRRAAAAAAAAAAAP PPPPPP!!*
His sickening belch extended for several seconds before Naruto sighed with relief, and blissfully gave his belly a hearty pat afterwards as he laughed to you and your unamused attitude. "....Good one, boss..." you say very flat. Naruto didn't mind, he simply smiled and said, "Thanks for your help. I think that burp just about cleared up enough room..." he said with a smile. You glance curiously at the older boy. "Enough room for what...?" you ask nervously. Your answer came in the form of a loud violent rumble.
*GGGGGUUUUURGLE!*
You looked down, sure enough, the source was Naruto's stomach. You glance back up, only to see Naruto glaring down at you, hungrily licking his lips.
"...Oh." You say bluntly. But before you can act, Naruto grabs you by both your shoulders and with surprising strength, hoists you right off your feet and up just above his mouth. "Don't feel too bad, my little morsel. At least you'll be one with the best." he said tauntingly. Before you could reply, he opens his mouth wider than you'd ever seen before, and shoves you straight into his awaiting mouth head first. The stench was even worse than his burps from earlier as he gradually began to gulp you deeper and deeper into his eager stomach. Your body was cramped to no end as it eventually slipped into his stomach with an ample thud. The resulting force caused Naruto on the outside to lose his balance and fall flat on his ass, shaking your world completely as stomach juices splashed over your cramped body.
Outside, Naruto was sitting on the grass, moaning in utter bliss as he stroked his bulging belly, feeling you struggle for dear life. "Don't worry, little guy, it'll be over before you know it," he said. You struggle to fight him from the inside, but only manage to stir up the digestive bubbles, forcing a great deal of air up the boy's throat, which meant:
*BBBBBBBBBRRRRRRRAAAAAAAAAAAP!* "Ahhhh, that felt goooooooood," he said tauntingly as he gave his belly a firm pat. "You can struggle all you *URP* want, kid, but my belly isn't gonna lose this fight. Trust me."
Which each burp, Naruto shortened your air supply and sped up the digestion process. Your windows were narrowing. Suddenly...