Tell the whole truth

You explain who you are: A woman from another planet, one that isn't just women and where not everyone is as... well built as the two women you're speaking to are. You tell them you came through a portal and your ship crashed, at which point some busty police officers showed up and tried to arrest you. You stole one of their vehicles and escaped before crashing.

"The next thing I know, I'm being nursed back to life by two extremely thicc and beautiful women..." You blush and shrug, trying to act casual, but the two women are mostly ignoring you. The younger one got more and more excited as you told your story, and when you finished, she turned to the one whose lap you're laying in.

"Are you thinking what I'm thinking?" She asks her colleague.

"Ummmm... yeah! I mean, like, maybe?"

The younger girl smiles and places her hand on the other girl's juicy thigh. Maybe they're more than colleagues...

"She's not from here, so they don't have her Boobprint on file, so she could sneak in to the Pink Pyramid..."

"And be our spy!" The girl bounces in excitement, shaking you on her lap.

"That's right." The younger girl grins and leans in. The two girls kiss, the one with you in her lap moaning softly. When they finish, the younger girl looks down at you. "I'm Lena, this bimbo is my friend Kimmy. We're members of the ASS Resistance." She smiles at you, proudly.

"Bimbo?" You ask, looking up at the woman holding you. You've never heard that word used as anything but an insult, but that's not how this girl, Lena, used it. Now, though, you can't help but recognize that it's a fitting label for her.

Lena ignores your question and keeps going. "I don't know how things work on your world, but here, a woman's breast size is directly tied to her social standing. The Queen has the biggest tits in the world, and everyone else is smaller and smaller until you get to the more average girls like me."

"Like you?!" You can't help but react. "You're average?" You marvel at the young woman's tits, so much bigger than your own.

"Yeah... we don't really... have people like you." She says, trying not to look at your flat chest, which the tight spacesuit you're wearing is doing no favors to. "But don't worry, we stole a Body Mod device. We'll get you fixed up." She winks at you, and though you're as confused as ever, it still turns you on.

"So, just so I understand, you're rebelling against this ridiculous society where women are judged by their bodies?"

"No no no," Lena shakes her head. "This world is a paradise. Everyone is happy, everyone is treated fairly. Everyone's body is beautiful, from the pizza delivery women to the queen's consorts. We just... like asses more than tits. That's why we're ASS Girls." Lena shrugs.

"Doesn't Lena's butt look great, too? I love her titties, but her ass..." Kimmy chimes in, licking her lips and giggling. "Show her, baby!"

Lena smiles and rolls her eyes in mock-frustration, then turns around and pull down her tight booty shorts, revealing a perfectly shaped and smooth ass. You feel your heart start to race as Lena playfully smacks her ass, the sound ringing through wherever this secret lair is. Then she bends over, proving she's much more limber than you'd expect for someone with her body type, revealing a diamond buttplug between her cheeks.

"Oh fuck!" You can't help but blurt out in a moan, your face turning bright red and Kimmy getting overcome with giggles. From your position between her legs, you suddenly feel some warmth emanating from her body and you realize that little show may have worked on both of you. You look up at Kimmy, who smiles down at you, and you sit up next to her.

"I'm glad you like it." Lena stands back up, kicking her shorts away and choosing to stay half naked. "I can get you one of your own, if you agree to help us out... The ass, I mean. Not the buttplug. That was a gift, and I don't know you that well... yet." She winks at you again.

"How? And help you out with what?" You try to push your horniness out of your mind.

"The how is easy, thanks to the Body Mod system. We're not all locked into the social standing we're born with, that would be barbaric, but our tits still have to reflect our position in society, right? That's why Mods were invented. Get a promotion at work? Get a Mod for bigger breasts. Get elected to the senate? Get a Mod for bigger breasts. Win the lottery? Get--"

"Okay, I get it. I mean, as much as I can... this isn't a thing on my world. Some people got surgery for bigger breasts or butts, but it... wasn't the same."

Kimmy gasps. "You come from a world where people wanted bigger butts and got them?"

"Oh, yeah. I guess so." You shrug. Kimmy and Lena smile at each other. "A lot of people like big butts on my world. There was a guy who wrote a song about it..."

"A guy?" Kimmy asks. "You have guys?"

"Yeah. You don't?" You ask, realizing why this planet is such a paradise. A bunch of boob and butt-obsessed women with no men... maybe you should stay here, mission be damned.

"No, not really." Lena explains. "But anyway, we want to infiltrate the Queen's headquarters, the Pink Pyramid, and try to convince the Queen to embrace asses in addition to boobs. We figure if she gets a load of someone with a nice butt, she'd give in. But we've never been able to figure out how to do it. The government has our boobprints on file, so if our tits got within a mile of it, we'd be captured."

"Then what? Thrown in a dungeon? They... shrink your tits?"

"Goddess, no!" Lena looks horrified. "Nothing so monstrous. They wouldn't really do anything... just send us home. But we owe it to the other ASS Girls to try! Me and Kimmy and our other friends and... maybe you?" Lena asks, reaching for something on a nearby shelf. She hands it to you: A black arm band that says "ASS" on it.