Punch at the lights

You wait for the perfect timing and hook a sucker punch at the greatest density of lights. Your fist cuts through the water, collides solidly with rubbery flesh and... that's it. The creature doesn't even flinch. It feels like you just punched a rubber bag of sand.

"S'alright, fine, if yer gonna be mean I can be even meaner." The voice hisses as a thick rubbery tube of flesh snaps around your torso, squeezing tight for a moment before loosening. Your middle body is now covered in more of that slime and, to your horror, your arms are stuck fast to your sides. The slippery monster coils lazily about your body. It bites your buttcheek and you become very aware of its needle-sharp teeth. You try to flinch away at the pricks of pain but the body enveloping you and your bound arms keep you from doing much of anything.

Two hands grab your buttcheeks, forcing them apart before you can react, and you feel a warm, slippery tongue or tentacle flick your asshole. Try as you might you can't stop your hole from slowly yielding to the probing appendage, shuddering with pleasure as it burrows deeper and deeper up your ass.

In spite of yourself you become hard, your erection bumping against the creature's long torso in the water. Your attacker wastes to time in shifting its body to trap your cock between two loops of its body. It's still producing some kind of slime that coats your length, making it easily glide through the tight gap.

The tongue squirms within your asshole, sending your body shuddering with pleasure. With every twitch your cock rubs against flesh and you can rapidly feel an orgasm mounting. Your balls tighten and with one final twitch you feel yourself emptying your balls into the water.

Your body goes slack as the coils loosen, and in the darkness you barely notice when you slip into unconsciousness...