Suggest you start with oral

"Why don't you eat my ass while I suck your cock?" you say.

"Interesting..." the serpent says. "Not the typical approach. However, I don't think your mouth is big enough for both of them."

"Them?"

As you watch, a spot on the serpent's underbelly, where the scales are small and pale, opens into a slit, and from within the beast's body, two pale pink cocks emerge. Each head is about the same girth as your own, but they grow wider as they go down. More than a foot in length, each slick rod of serpent meat quivers before you, and you lick suddenly dry lips.

"I can try," you say.

"Very well," the serpent says, and lift you into the air again, turning you until your ass is in the air and your face is inches away from the twin cockheads. You feel his cold, slippery nose press between your cheeks, and then his slimy tongue begins to lap against your hole. You cock hardens immediately and you stifle a groan as you overly-sensitized body shudders with pleasure.

You open your mouth and lean down, taking one of the cocks into your mouth, licking and suckling the tip. The serpent makes a pleased noise and presses his tongue into you. It feels as thick as a cock, but slides much deeper, licking and twisting inside of you. It licks across your prostate and you gasp, your legs kicking involuntarily. The serpent seems to think that is a good sign, because he begins to thrust his tongue into you, pounding against that spongy lump of nerves until you writhe helplessly, each ragged breath ending in a long, hoarse moan.

You can feel your orgasm building, the pressure growing, when he pulls back, leaving your ass empty and aching. "Am I distracting you," he asks, "or is it too hard to reach? Maybe this will help." He lowers you, pushing his cock further into your mouth and you try to pull back as it nears the back of your throat, but strangely enough, it doesn't make you want to gag. You lean forward, taking more, and as the head of his cock fills your throat, you realize that if you can survive underwater without breathing, you don't have to worry about trying to breathe around a cock, either.

Bobbing your head, you let the serpent's slick shaft slide down your throat, moaning as he drives his tongue deep into your ass again. Each thrust of that tongue rocks you forward, pushing you farther onto his cock, until your not so much sucking his cock as he is fucking your throat. His other cock rubs against your face, leaving a cold smear of thick fluid on your skin. You are helpless to stop him, but with your cock throbbing and your nuts so full you feel like they're going to burst, stopping him is about the last thing on your mind. You swallow, your throat muscles squeezing that slick pink shaft, and he rumbles with pleasure, the vibrations sliding down the length of his tongue and tipping you over the edge.

Your body stiffens, legs kicking as you cum hard, splattering his thick coils with your jizz. After the final spurt, you hang limp in his grasp, your head spinning, and after a moment he withdraws his tongue and lifts you off his cock.

"That was quite pleasant," the serpent says, "but I'm afraid I didn't finish. The sorcerer said he wants to see me cum in you, so I suppose that means we better get on with the show." He turns you around and tries to lower you onto one of his cocks, but his slippery pole misses your slippery hole, and his cock rubs up the middle of your back. He tries again, but this time, his cock slides forward, and between your legs, up past your balls.

"Let me help," you say. "It'll be a lot easier if I can use my hands."

"I don't know, you might try to escape again," the serpent says.

"I won't," you tell him. "I know you'd just catch me again, so it wouldn't do me any good to try."

The serpent regards you for a moment, then the coils around you loosen, and he sets you down astride his thick body, in front of his double cocks. "Don't make me regret trusting you, human," he says.

You rise up on your knees and reach back, your fingers brushing over the two slippery shafts.