You decide that discretion, in this case, is the better part of valor. The zookeeper sees this, and sighs. "Well Bobby, looks like you get me today," he says, and strips off his shirt. To your surprise, he has a black cloth strapped across his chest. He removes his shoes, pants, and boxers next, letting everyone see that he's a trans boy, and obviously pre-op at that. He keeps the binder on, though, for some reason. You wonder if it's digestible. His brown locks of hair fall down over his face after he stands back up, and you can't help but notice how cute he looks.
He turns around to face the snake, and grabs a small bottle out of a hidden compartment disguised as a rock. The snake reacts immediately, sticking its tongue out, and after a second, its cock protrudes from where it hid towards the end of the snake's body. "Unlike most snakes, which have two barbed 'hemipenes'," the guide explains, "Bobby here, and all great anacondas, have one singular penis which they use for both reproduction and grasping prey. You can see here," the guide points at a gland on the head of the smooth pink penis, "he has a detector gland. When great anacondas breed, the female gives off a protein which tells him that she's been successfully impregnated. If not, he eats her to regain some calories, and also as an easy meal, since he'd already be wrapped around her at that point. Bobby here currently thinks I'm a female anaconda because of the pheromones I just sprayed, and-"
The trans boy leans against the body of the snake, who has reared its upper body in curiosity, and guides the snake's cock into his waiting pussy. He tenses up as the snake's shaft slowly sinks into his hole, and groans in pleasure. "he'll try to breed me first, but after he figures out I'm not getting knocked up, well, I'm his next meal."
The trans boy starts bumping up and down on the snake's cock, and the snake coils up and down along in rhythm. "Fuck!" The trans boy exclaims, then covers his mouth and blurts an apology. The snake fucks him faster, and its whole body seems to tense as cum spurts deep into his body. "So," the guide says with a pant, "he'll probably give it a minute to see if it'll take or not. With these snakes, they're pretty hard to breed in captivity, so what we do is implant a human volunteer with an anaconda female's eggs to be fertilized. Bobby here is quite the gentleman, usually, and will even fuck a cis boy in the ass first before deciding whether or not to eat. Teeny, though," he points behind him where you can see the massive head of another anaconda poking out of the water, "on the other hand, will just eat his partner immediately if he doesn't sense the proteins of anaconda eggs on the first thrust. In fact," the guide laughed, "we had a breeding volunteer earlier this month for him, he stuck his penis in the wrong whole, and immediately ate her. She wasn't happy about that, let me tell ya!"
The snake stirs, and you guess that means that it's decided that it has waited long enough. The trans boy's cute face disappears suddenly as the snake lurches down, gulping him up, and you watch in fascination as his body is lifted up in the air, beads of white snake ejaculate running down his legs as he's eaten. His legs disappear into the snake's maw, and the snake eyes the crowd carefully, before deciding that there is no threat and turning around, silently slithering into the water behind him, leaving behind only its keepers carelessly-tossed uniform lying on the ground.