Jon the helper

Jon headed downstairs to find his mom speaking with a 12-year-old girl. He recognized her as Mckenzie Smith's younger sister Allison. Mckenzie was one of the cutest and most athletic girls at a rival high school. Jon had heard of her repeatedly; her family lived two blocks down from Jon. As soon as Allison saw Jon, she grew excited.
"Jon! Kenzie was in a car crash and she knocked out her front tooth," said Allison, bouncing up and down. "The dentist is gonna make a replacement, but it'll take four days. Kenzie can NOT be seen in school with such a big problem. So, she sent me to tell you that you're gonna be her replacement tooth for four days." Allison giggled and jumped up and down again. "Oh this is so COOL!" she squealed. "I've never seen this happen before! Here we go!" She pointed at Jon, who suddenly felt dizzy and blacked out.
When he awoke, Jon was in a pitch-black cave of some sort. He couldn't move, but he could feel the cave's walls touching him. They felt slimy and smelled weird.
Suddenly the walls in front of him opened, and Jon saw light.
"Like, oh my gosh," boomed a high-pitched girl's voice. It resonated all around Jon. "My tooth is like, totally fixed!"
Then Jon remembered where he was. He was the tooth of Mckenzie Smith for four straight days. He saw a massive pink object rise in front of him; it pressed against him repeatedly. He recognized it as Kenzie's tongue. Her lips parted again, and Jon had a view of Kenzie smiling wide in her bathroom mirror. She was so hot.
"This is, like, perfect," said Kenzie. Every time she spoke, her tongue pressed against Jon and her lips opened and closed over and over again. Jon could see, smell, and taste the inside of Kenzie's mouth.
"Thanks, sis," said Kenzie. Every word boomed around Jon due to his location and size. "I'm off to lunch with James!" Jon realized he would have a front-row seat to whatever food she ate.