"W-well, I wouldn't mind being in your navel," you said, eyeing the little divot on her belly that was framed beautifully by her sweatpants and tank top.
"Okay then!" Sammy picked you back up, and as she lowered you down to her belly button she took a few moments to let her flab jiggle a bit, relishing your flustered squirms before putting you inside. "There we go, nice and snug—ah! Ahehah!"
"Y-you alright?"
"I'm fine, I-I'm fine! I-it's just—eeheehee!" You had to briefly grip the navel walls to avoid falling over from the laughter-adjacent earthquake. "It's just my belly can be rather sensitive to touch~!"
"Oh... Uh, perhaps I should move elsewhere on y—"
"No, no, it's fine, aheheh... It won't be hard to mask this for Pauline."
"If you say so." Relieved, somewhat, you began walking around inside Sammy's navel, which was... remarkably deep. And quite soft, though you'd be shocked if it wasn't from how gloriously chubby she was. There wasn't much light filtering in, though, so you had to feel around to make sure you didn't bump into anything—"Huh? Is this... a chunk of apple?"
"Oh! Yeah, some food tends to get stuck in there when I skip showering for a day or two—old habits from my Munchlax days die hard, I guess. Uh, feel free to eat anything you find if you want to! I'll be out talking with Pauline."
"Gotcha!"

You gradually got used to the shuddering every step the Snorlax took caused, and began partaking in the schmorgasbord of massive crumbs in her navel—all remarkably delicious!—as Sammy walks back out to the living room. "Hey, Paulina."
"Hey Sammy. Ooh, looking good." You felt the Purugly patting her girlfriend's outfit, knocking you down and making Sammy chuckle from you tumbling inside her sensitive belly button—which, thankfully, was masked by Pauline touching her at the same time. "All set for the party, then?"
"Hahah, yep!" Sammy drummed her belly, breifly hiding your light as you sat back up. "Figured I'd show off my gains to the girls tonight."
"Heh, what gains?"
"...You know what I mean," she said, snickering. "Hah, maybe we should have a nice dance-off during girls' night."
"If you want. Diana would probably win if she shows up, though."
"Oh yeah, that Dragonite is amazing at shaking her thing. Her and Giana make a good pair."
"You'd win in a little eat-off, though!"
"Nah, that's a toss-up between me, Harley, and Ursa."
"Ooh~ some humility from you, I like it~"
"Ahaha! Don't expect it too often." She laughed it off, leaning back on the couch with a smile as she rubbed her gut—mainly around her navel, as you peeked out. So that's another girl you might see tonight... You were already feeling your mind race picturing Diana, with her chubby draconic body pulling off alluring dance moves and swaying her ass hypnotically above you. Though you supposed you'd have to wait 'til tonight to see for yourself.