Side with Mia

You weren't a big fan of Ava since you first saw her, so it would make sense to help Mia in taking her down. You quickly run up to the sisters and try to push Ava. She budges, slightly, but still gets put off balance.

She manages to say "HEY!" before Mia topples her to the ground, moving behind Ava and putting her in a **** hold on her back.

She struggles hard, but Mia manages to keep her in place. Ava doesn't give up easily, and flails her body around for a few minutes, but tires herself out.

Mia says "You done, crazy bitch?"

Ava replies, through her panting "Fuck off! Let me go!"

Mia laughs and says "I don't think so. It's time you finally get what's coming to you, and Jason's going to help me with that. Go ahead man, fuck her ass."

Ava and you both seem surprised, but she is not nearly as happy as you about that statement.

Ava looks angrily at you and says "YOU! If you even think about fucking me, you're dead! I'll kill both of you! Don't fucking try-"

Ava's yelling is cut short, by Mia's cock being jammed down her open mouth. Holding Ava's head firmly with her hands, Mia took the opportunity to shove her 8.5-inch dick down her sister's throat.

With a moan of pleasure, Mia says "Shut the fuck UP already! Damn, it feels good to shut this bitch up for once. Well, her ass is yours now, so have fun."

You spit in your hand and start rubbing your cock, quickly bringing it to its fully erect state. You press the tip of your dick up against Ava's tight ass. You feel her clenching her ass, obviously not wanting to get fucked, while still trying to shit talk you with a cock down her throat, only producing a garbled mess of sound. You, however, push forward and penetrate her. She moans, sending vibrations all around Mia's cock. Her ass is tight, but you slowly move your wet cock deeper and deeper in her anus. Finally, you feel your hips making contact as you slide balls deep her ass. The walls of her rectum squeeze your dick hard, giving you the rush you need, to start pounding her ass. With great speed and ****, you start fucking Ava's ass, making belly jiggle with each thrust. You can see a fair outline on the surface of her stomach of where your cock is located in her ass. Mia watches, still holding her massive dick down Ava's throat, and starts getting horny.

She says "That's right! Give it to her! Watching you fuck my bitch of a sister is getting me hot... Let's see how you like this, you cunt!"

Mia pulls her cock swiftly out of Ava's mouth, giving her a few seconds of rest.

Ava coughs a few times and says "YOU'RE ALL FUCKING DEA-" before having Mia shove her hot shaft down her throat again.

She begins moving back and forth, face fucking her sister and bulging the bottom of her neck with her dick. You follow up with Mia's rhythm, making so that you both fill up Ava simultaneously. As you pound away at Ava's holes, you notice that her cock is slowly rising and getting hard. Is she into this? You don't know, but keep on fucking her. Soon enough, her cock is fully erect and throbbing, with a layer of precum covering her tip. As you pound her ass, her massive dong starts swinging around, almost hypnotically. You move your hand over to her dick and start rubbing the tip with the palm of your hand. Ava moves her hips upwards, being surprised by the sudden sensation. You move your hand in front of your face and see that it's covered by a thick layer of her precum. It has a strong and arousing smell, and you can't help but have a taste. You lick your hand clean, giving you a rush of pleasure when tasting the sticky fluid. It makes you want to get a taste from the source.

You lean your head down and take Ava's dick in your mouth. You swirl your tongue around her tip and start bobbing your head up and down. You take her as deep as your position allows, which is almost halfway. You continue fucking Ava's ass while sucking her off at the same time and Mia pounding her throat. As Mia gets closer to her orgasm, she starts speeding up her thrusts and you barely manage to keep up with her speed. Your own impending climax gives you some extra stamina, to finish the job. You and Mia cum at the same time. Mia unloads a flurry of giant cumshots down her sister's throat. Ava seems to struggle to swallow all of the cum in her mouth, but she tries her best. She's practically chugging her sister's cum when finally she can't keep up with the amount, and it starts dripping from her mouth and out of her nose. You cum too, flooding Ava's ass with your jizz, but not cumming nearly as much as Mia.

While you're in the middle of stuffing Ava's ass with your spunk, her cock starts twitching and throbbing in your mouth. You know what this means, and happily, await Ava's load by sticking out your tongue from the bottom of your mouth. Ava frantically twitches and moves her hips as long and thick ropes of cum start shooting out of her cock. The first few hot batches of her seed land straight in your mouth. You quickly start swallowing as much as you can, tasting her thick and salty sperm as it slides down your throat. After swallowing a dozen loads you pull away from Ava and clean out your mouth. Ava starts spraying cum straight up, and it lands all over her tits, stomach, and her own face.

Mia gets really aroused by this scene, and says "Holy shit, she really does cum a lot. Well, since you like her cum so much, can't hurt to get a taste too..."

She leans forward and puts her mouth around her sister's cock, letting multiple loads enter her mouth. She moves forward, even more, making her own dick slide further down Ava's throat, and taking Ava's cock down her own throat as well. As the girls empty their balls into each other's mouths, you see Mia struggling to swallow her sister's incoming sperm loads, as they quickly fill her mouth up. When both of their orgasms finally end, Mia slowly moves her head off of Ava's dick and you can tell she's got a full mouth of her sisters seed. She leans in, close to your face and presses her lips to yours. You don't resist and share a cum exchanging kiss with Mia. You explore each other's mouths for a bit until you both have an equal amount of Ava's sperm. Mia breaks the kiss and swallows. You do so as well.

You both rip yourselves from Ava's ruined holes and take a seat on the couch. Ava lays on the floor, her mouth and ass leaking cum. She dazes off to sleep.

Mia looks at you and says "Wow, thanks a lot for teaching this bitch a lesson. You have NO IDEA how annoying it is to have to listen to her scream at me all day, and not being able to do anything about it. Good thing this test came around, so I can finally get my way with her. And thank you for helping me take her down too!"

Mia smiles sweetly and you smile back, saying "No problem, I had a lot of fun too! She never did strike me as the friendly type, anyway. Well, it's been fun, but you know, more testing to get to..."

Mia says "I get it, I get it... Well, good luck with your tests, and thanks again!"

You hug Mia and go back to your own room. As you look over your shoulder, you see Mia doing the same, and Ava still having her well-deserved nap.

You got the "Comradery" ending with Ava and Mia.