You swim upwards, away from her nether regions. You don't want to get stuck there, after all. It's difficult to see much in the water, it's dark since you're overshadowed by Kim and you try not to keep your eyes open since the chlorine burns them a little. You pass by her mammoth breasts as you near the surface, and realize it's still strangely dark.
Finally you reach the surface and wipe the water away from your eyes. Around you, it's too dark to see a thing, and while you think you feel hot air around you, you figure it's just from the warm water of the jacuzzi. Below you, you notice there's some light coming up from the water, but not enough to illuminate your surroundings. Finally you take a breath through your nose and the air around you smells... minty?
"Mint? Oh shit, Kim! No!" you shout, but it's to no avail.
Kim doesn't hear you, but about the same time you shout she closes her maw around you and lifts her head, allowing the water to begin draining out.
A small giggle reverberates around you as she traps you in her mouth. You initially land on her closed teeth as she raises her head and the water is released, but as she lifts it you're dropped onto her tongue. It's seething hot, and her powerful tongue wastes no time tormenting you. You're slammed against the roof of her mouth as she tastes you, and apparently you taste pretty good considering the "Mmmmm" sounds escaping her throat. After a few seconds of taste testing, she pulls her head back and opens her mouth. You can see yourself slipping toward her throat now, and you struggle to grip her tongue. It's too big and soft though, and eventually you pass her tonsils. With an audible gulp she handles the rest, sending you to her waiting stomach.
"Ahhh. Fantastic. You said you were indestructible right? So you should be fine in there for now," Kim comments, patting her trim belly. She decides she better get back to the park since Melissa had gotten on to her before for taking extended breaks. She puts her lifeguard swimsuit back on and makes her way to her post.
You're squeezed down her esophagus and after a few seconds, you're forced into her stomach. It's shifting wildly as you enter, but it quickly dies down to a more rhythmic swaying as Kim walks. It appears to be empty, at least until Kim drinks a swig of water.
"Don't worry, I'll let you have some fun in the park too," she laughs after she drinks half a bottle of water.
The water fills the bottom of the stomach, so you swim to one end where it's more shallow. Kim takes her position on the lifeguard seat at the wave pool and things calm down a lot for you.
It's pretty uneventful for what seems like at least a couple hours. It seemed a hell of a lot longer to you as you were trapped inside Kim. Your eyes had adjusted to the minimal light you had, and you could see that the esophagus was far out of your reach. Unless Kim gets you out of here, the only way is going to be through her intestines after she has a meal. While you were almost positive you could survive her stomach acid - you'd been eaten plenty of times before, often landing in digesting food - you had never actually made the whole trip through the digestive system.