Adult-FanFiction.org : Cartoons

Falling for Gravity part 2	By : Fanfictionfan360 Category: +G through L > Invader Zim > Threesomes/Moresomes Views: 1146 -:- Recommendations : 0 -:- Currently Reading : 0
Disclaimer: I do not own Invader Zim and Gravity Falls or their characters, Jhonen Vasquez and Alex Hirsch own those rights, I am not making any profit for writing this

Chapter List
- 1-Falling for Gravity part 2
- 1
Falling for Gravity part 2
(Invader Zim/Gravity Falls crossover)
After the initial awkwardness of their official meeting it didn’t take long for it to be shrugged off with Dib and the others quickly settling in to the guest rooms at the Mystery Shack, Gaz being happy to find that the Shack had both electricity and internet access allowing her to set up the games consoles she had brought with her
Unfortunately for her however she wasn’t given much time to enjoy her games before she was forced outside to ‘enjoy nature’ leaving her stood awkwardly outside of the Mystery Shack somewhat socialising with Mabel as they watched GIR play with Waddles “soooo...pigs are cool” she commented, happy that Mabel at least shared a favourite animal with her
“I know right?!” Mabel beamed back, when she was younger Gaz would have found her peppiness annoying but with her maturing she found it almost adorable now “the moment I first saw him I knew I had to have him!”
Nodding in agreement Gaz made a mental note to look up pet piglets for sale when they got home before turning her attention back to Waddles and GIR, the Robot now riding the Pig like a bucking bronco whilst wailing and cheering gleefully in delight, Mabel smiling at the sight before speaking again “so your brother, is he single?”
“Forward aren’t you? I like that” Gaz smirked back “technically yes and no, he calls Tak his girlfriend but she insists on an open relationship, something about ‘people not being naturally monogamous’, I don’t really get her reasoning but I don’t bitch about it, it just means I get to bounce on Dib’s dick without her trying to claw my eyes out for it”
“.....you fuck your brother?”
“Ehhhh, it’s more ‘brother’ than actual siblings, we’re not blood related, long story” Gaz explained flexing her fingers in air quotes around the word brother “let me guess, you want a taste of his dick?”
“God yes, barely any new guys come through here when me and Dipper come to stay here and toys just don’t do it for me anymore” the brunette admitted, one of her hands starting to slide down her body as she was already fantasising about what Dib’s cock would be like
Biting her lip at the sight Gaz reached over to take her hand to pull her inside where Dib was when her attention was taken by Zim coming out of the woods, the Irken holding a strange device making it obvious he had been spending the morning exploring and scanning things, more so out of curiosity for his new home rather than searching for weaknesses “change of plan, we’ve got a big dick coming our way right now” the Goth slut purred before calling Zim over
“What do you want, Gaz-thing? Zim is very busy, sooo busy!” the Irken announced with his old dramatic flair making Gaz smirk before she simply flashed him using one hand to pull up her shirt whilst using the other to pull up Mabel’s sweater to expose her huge EE cup breasts, the sight of which immediately shutting Zim up for a moment “Zim....may have some time for a break”
“Damn straight you do” the Goth whore stated leaving her tits exposed as she then grabbed Zim by his shirt, keeping a hold of Mabel’s sweater with her other hand she then proceeded to drag them both into the treeline leaving GIR to continue playing with Waddles
When they were appropriately out of sight of the hyperactive Robot Gaz wasted no time in stripping down, Mabel giggling as she eagerly followed suit leaving Zim staring at both of them as they revealed themselves without shame, Mabel revealing herself to be almost as curvy as Gaz and whilst she was smaller in the ass department her tits easily dwarfed Gaz’s being an easy double J cup
Noticing how much Zim was staring Mabel giggled and shook her tits for him, loving the attention whilst eying the huge bulge in his pants “wow he looks huge” she moaned before gasping “I’ve got the perfect thing!” she then exclaimed excitedly as she fully removed her sweater and started to rummage through it, pulling out what looked like a flashlight
Before either Gaz or Zim could question her as to what the flashlight was for Mabel shone it on Zim’s groin and a moment later his cock burst free from them, even larger than before to hang at an easy twenty inches, Gaz’s eyes nearly popping out of her head at the sight of it with utter shock and lust, her legs starting to shake before she fell to her knees and gently took hold of Zim’s new monstrous cock “oh my god…this is going to fucking ruin me…” she moaned as she started to lick up and down his length
Biting her lip as she watched Gaz drool all over Zim’s new much larger cock Mabel threw the flashlight aside before kneeling down to join the Gothic slut, taking her place at the other side of Zim’s cock to join her in kissing and licking along the Irken’s manhood seemingly intent on proving that she was just as much of a slut if not more so than Gaz
Seemingly noticing Mabel’s attempt at one upping her Gaz was more than welcoming of the challenge as she moved to the head of Zim’s dick and opened her mouth as wide as she could to take in the now much larger cock head, her jaw straining and lips stretching as she forced herself forward, having watched enough huge cock pornos to let herself be intimated by one in real life
“Mmmppph that’s hot” Mabel moaned as she then moved to allow Gaz more room to deep throat Zim as far as she could, her throat bulging obscenely all the way down to her ribcage as she continued to let out muffled gags and chokes, her hands gripping at Zim’s hips as she refused to let herself pull back
As Gaz hit her stopping point at sixteen inches Mabel moved in to work the Irken’s balls, letting them weigh heavy on her tongue as she knelt beneath Gaz feeling her tits against her back before she then started his balls into her mouth making her cheeks bulge out as far as they could go
With both girls working his cock and balls Zim didn’t last long, his body shuddering and his head rolling back as he came down Gaz’s throat taking the Goth by surprise as she quickly found that the flashlight had not only made his cock and balls bigger but also his cum output, making Gaz shoot back coughing and gagging from the sudden overload of cum in her throat causing Zim to finish his load all over her and Mabel, the brunette letting out shrill coos of bliss as she revelled in the sudden cum shower
“Ooooh fuck yes! This is what I needed!” Mabel exclaimed joyfully, cupping and lifting her tits up to make them easier targets for Zim’s cum load, cooing and mewling as her heavy breasts were pasted with stream after stream of the thick Irken jizz
“God you’re a fucking slut aren’t you?” Gaz praised her, leaning forward to lick several strands of cum from the brunette’s cheek making the younger girl giggle at the feeling before she turned to to face and kiss Gaz, the two girls quickly wrestling tongues with lustful almost pornographic moans making Zim’s cock twitch as he stood watching them
Deepening the kiss borderline sucking on Mabel’s tongue Gaz took hold of her and pulled her towards herself whilst lying back until Mabel was laid out on her front, their tits pressed together as Gaz then ran her hands down the brunette’s body, cupping her ass and spreading the cheeks to reveal her tight fuck holes to Zim making it obvious to him what she wanted him to do
Happily taking his place behind Mabel Zim took hold of her shoulders before starting to press into her tight ass, making the brunette gasp breathlessly as her eyes went wide and her pupils turned into hearts “that’s it, you like a good fat cock deep in your guts don’t you bitch?” Gaz praised her to which Mabel just moaned with bliss in response “oh we’re definitely keeping you”
As Zim started to harshly pound into Mabel’s ass Gaz wrapped her arms around her to keep her in place, biting her lip as she enjoyed the expressions of slutty ecstasy on the brunettes face along with enjoying the feeling of their clits rubbing together every time Zim rammed into her “fuck yes, harder, rut this slut harder, god I can feel you in her stomach” Gaz panted as with every thrust Mabel’s stomach bulged and poked against hers making her toes curl as her orgasm steadily built up
Mabel on the other hand was suffering an orgasm roughly every ten seconds, her brain completely melted from pleasure as she clung to Gaz with everything she had, her words coming out as a garbled mess as her clit rubbed furiously against Gaz’s, bringing the Goth whore to orgasm after she hit her twentieth, making her throw her head back with a cry of bliss that echoed out through the forest around them, Mabel screaming soon after her as Zim came hard in her ass roughly a minute later
Her stomach bulging slightly from the sheer amount of cum getting packed into her Mabel then collapsed forward, having completely blacked out from pleasure making Gaz smirk as she admired the brainless look of bliss on the younger girls face “oh we’re definitely taking her home, when we leave let’s stick her in the trunk when no one’s looking” she grinned making Zim looked at her confused
“Zim is never sure if you are joking or not”
Thank you for reading, hope you enjoyed it
- 1
You need to be logged in to leave a review for this story.
Report Story

Falling for Gravity part 2