They were here because of that accursed Spider-Man. He had trapped them in a small, dark room with nothing to live on but love. The sisters turned to each-other with lustful looks in their "eyes". Life is hard trying to live in a dark room, but speaking of hard...
They heard Spider-Man's voice through the speaker in the corner of the room. In a sleazy tone, he says "You know you gotta do..."
Agony retracted her sleek, purple mask showing her beautiful face and full lips, and Scream does the same, licking her lips at Leslie, as she grinned before they both embraced one another and locked mouths, as Donna walked Leslie into a wall with extreme force, forcing Leslie to grab hold of her ass, and started spanking her firmly, gaining a short groan from her mouth "Uh," moving their mouths apart briefly every time, saliva dripping from both of their mouths. As Leslie firmly held and squeezed Donna's round, soft ass the sisters both slumped to the ground crossed their legs over each other's. They retracted their mouths from one another, strings of saliva sticking between their full, plump red lips, and as Donna licked her lips she said, "Mmm..."
As Donna looked down, she noticed that the saliva dripping from their mouths had gone all over Leslie's amazing chest, and as she smiled a lovely smile with her plump lips, she moved her head down and licked all the spit off of Leslie's massive breasts, to Leslie's surprise, and to her further surprise, grabbed hold of her soft, round breasts and stuck her face right in, all she could see was the purple of Leslie's skintight costume, as her hands moved up and down her amazing chest, caressing her lovely curves, until she could feel Leslie's stone hard nipples, as she placed her index fingers over them and rubbed them up and down, sending shivers down her spine, but we'll get to her back later...
Spider-Man's aroused voice came through the speaker again "Dat booty tho." The two sisters raised their eyebrows at each-other, and Donna stood up, facing away from Leslie, still slumped in the corner looking at Donna's lovely, round ass as Leslie once again materialised her symbiote mask, and with sharp, needle-like fangs jutting out of her mouth, she bit into Donna's massive, soft ass, and Donna screamed loudly as her liquid costume started to foam, and Leslie stuck both hands out and grabbed Donna's ass, groping and squeezing it, Donna trying to hide how much she was enjoying the pain as Leslie pushed her hands into Donna's large, plump ass, moving them up and down, jiggling Donna's soft, round ass up and down repeatedly.
Spider-Man was annoyed at how he hadn't finished yet and shouted through the speaker "Time to get X-Rated!" The sisters looked at each other, and both sat down facing one another and Donna retracted her costume from her crotch showing her thick, pink cotton underwear, which Leslie caressed with her clawed fingers, rubbing against the sensitive skin of her groin, she then ran one finger down the middle of her body, reaching her deep camel toe and sending shudders down Donna's spine, before Leslie grabs her underwear and rips it off, bringing a smile to both their faces as their masks both re-materialise and a sharp, prehensile tongue, dripping with green slime crawls out of Leslie's mouth, swooshing down toward Donna's crotch and jutted between the intricate, rubbery folds of her vagina, her sharp tongue and acidic saliva making Donna bleed, as she tried to hide her excitement from the pain, but Leslie could tell how excited she was, as her nipples were solid and pointy, so Leslie placed her fingers over them and rubbed up and down, simultaneously groping her soft, round, bouncy breasts as they both slowly stood up, Donna grabbing Leslie's lovely soft ass, all the tension building as she squeezed her nice, big, plump ass with each finger squeezing making a temporary dent in her amazing ass as she jiggled it up and down, seemingly oblivious to the fact she was being penetrated by her sister, until she screamed loudly and Leslie noticed her tongue felt wet, and not from green slime. They paused for a second, but then threw themselves on top of one another, groping each other, and Donna said "I love you, sister" as they were writhing and grinding on the ground.
I also forgot to mention that sometime across the way, Spider-Man came.