As you sleep, the symbiote melts off your body, your cock lying flaccid and limp against your abdomen, the symbiote searches your room, looking for something. The symbiote passes pictures of a figure in a red and blue bodysuit with a spider on the front, it seems to nod and heads back to you.
The symbiote latches onto your hand, and starts to move up your arm, tendril after tendril wrapping around it. You moan in your sleep, seemingly having a nightmare. The slime coats your other hand as you grip your bedsheets tightly, arching your back, tendrils intertwining around your fingers. The symbiote starts to coat your chest, covering it in it's shiny black slime. It then starts to make it's way towards your feet, tendrils of goo sliding down your bare legs, coating your feet, you moan again from the sensations of the slime on your feet. Tendrils start to wrap around your cock, which quickly goes erect again, the slime coats your shaft and your balls, stroking at the tip before covering that too, you moan and writhe in pleasure.
The symbiote now sends tendrils up your neck and starts to cover your face, a white spider symbol starts to appear on your chest. The slime covers your face and you cum hard from the sensations of the goo jerking you off. White eye patches appear on the mask of the suit. With your body all coated in black slime, it tightens on your body, going from a thick slimy coating to a super tight and shiny black bodysuit, your erect cock twitching with pleasure, and your muscled chest heaving. The symbiote decides to have a little. . . Fun, while you sleep.