Actually, it was a test, and you failed

Just as you are about to leave, with or without Toby, the entire corridor seems to tilt. You lurch and then fall flat on your ass, the spongy floor at least cushioning your fall. You try to sit up, but you feel like you're sinking into slime. It's a gross, almost suffocating sensation. A quick glance to your right confirms that Toby is in the same predicament.

"INTERESTING. WE WERE ALMOST CERTAIN THAT YOU WOULD INVESTIGATE A POTENTIAL ESCAPE MECHANISM. HOWEVER, WE HAD QUITE THE DEBATE REGARDING WHICH OF YOU WOULD BE THE PIONEER. OUR DATA SUGGESTED THE MALE WOULD BE THE RISK-TAKER."

So this was some kind of test! You curse yourself for complacently falling into their trap. So much for showing them you're smart--to these aliens, you're just a jumped-up primate.

"You can't expect us to live in a zoo exhibit! We have rights!" you yell. But your heart isn't in it. You thrash in your little cocoon.

"IF YOU WERE TRULY A MEMBER OF A RATIONAL AND INTELLIGENT SPECIES, YOU WOULD REALIZE NOW THAT YOU ARE OUTMATCHED AND SUBMIT TO YOUR CAPTIVITY. THE VERY FACT YOU ATTEMPTED TO ESCAPE CONFIRMS THAT YOUR SPECIES' DEVELOPMENT LEVEL IS SUITABLE FOR OUR ZOO. YOU SHOULD BE PLEASED TO KNOW THAT YOUR EXHIBIT CURRENTLY RANKS NUMBER TWO ACROSS ALL OF KELTRAX, SECOND ONLY TO AN EXHIBIT OF A MULTI-DIMENSIONAL LIFEFORM THAT REPRODUCES BY INTERSECTING ITS TIMELINE AND IMPREGNATING ITSELF.

"IF YOU CONTINUE TO COOPERATE AND PLEASE OUR ZOO PATRONS, WE CAN MAKE LIFE VERY COMFORTABLE FOR YOU. FUTURE ATTEMPTS TO ESCAPE WILL BE FUTILE AND ... UNPLEASANT. WE WILL DEMONSTRATE HOW, SO THAT YOU CAN FULLY UNDERSTAND."

The slime cocoon thickens and engulfs your entire body. You struggle, but it's no use: you are utterly powerless. You feel the semi-liquid sludge cover you, flooding into your mouth, your nose, your ears. You expect to feel a drowning sensation. Instead it's like you just don't need to breathe. It is uncomfortable but not panic-inducing.

What is panic-inducing is the feeling of the slime creeping into your vagina and your rectum. It is warm, thick, thicker than water but not quite as hard as a cock. It stretches your cavities slightly, your cunt more so than your ass, and you feel it creeping further and further inside you, past your cervix and into your womb. This starts to stretch as it becomes a receptacle for the slime. Likewise your stomach and lungs fill up, and soon you are a bloated, fattened version of yourself.

You go limp, surrender. You can't see, smell, or hear anything any more. All you can feel is the invasion of the substance as it seeks to fill every nook and cranny of your exposed body. It feels strangely good, not exactly pleasurable, but almost cleansing.

Then it starts to burn.

You'd scream if you could, but of course you can't. You can't move at all, really, just endure it. This is not burning like fire, but burning like you left your hair removal cream on too long. It's a slow, itching, chemical sensation, all along the outside and inside of your body. It's not exactly agony so much as irritant.

Then you black out, waking up who-knows-when in the habitat. Toby is next to you, also regaining consciousness. He gasps and tries to cover himself, and when you look down, you see why: his cock has shrunk. Once decidedly above-average, it is now disappointingly small.

You groan, because you can predict what the Keltraxans have done to you. Sure enough, you look down and see your once-respectable tits have diminished into barely-there A-cups. Your formerly-full and sexy dark nipples are now tiny pink buds. You still look sexy, in a flat-chested, "I'm going to be mistaken as a twelve-year-old forever" kind of way. But you already miss that reassuring weight on your chest.

"OK, I get that this is a punishment," you say out loud, partly to Toby and partly to the Keltraxans. "But, uh, won't this kind of interfere with our, um, 'mating rituals'?"

The Keltraxans' reply is swift. "YOU WILL BE RESTORED TO YOUR FORMER PHENOTYPES IF YOU COOPERATE. DISOBEY AND WE WILL FURTHER MODIFY YOU. SHOULD THIS HAVE THE SIDE EFFECT OF REDUCING YOUR EXHIBIT'S RATINGS BELOW AN ADEQUATE LEVEL, YOUR EXHIBIT WILL BE DISCONTINUED."

Toby says, "Somehow I don't think 'discontinued' means we'll get sent back to Earth."

You nod in agreement. So that's that: the Keltraxans have thoroughly crushed any dreams of escaping this place. They've hit you with the stick and now dangled a carrot in front of you. But do you take it?