"No way!"
Sarah steps in front of Monica and plunges her ass into her face, "You'll regret ever challenging me, Monica." Sarah lets out a grunt and...
PPPPHHHBBBBTTTT
Sarah's fart was super powerful. Her fart blew Monica's hair wildly. Monica just stood there, disappointed, "Is that all you have? Pathetic. I'll show you what a true fart smells like, now turn around and lie down."
"Fine, just stop acting so cocky."
Sarah turns around and lies on her back. After Sarah's finishes, Monica too turns around and plops her ass on Sarah's face, keeping her feet under Sarah's head, so that she can prevent Sarah from backing out, "That last fart was just a warm-up, the real contest starts now!" Monica lets out a soft grunt and...
Lets out a big, bubbly fart that completely overwhelmed Sarah in volume. Until now, Sarah was holding her breath, but she then decided that it was time to see what Monica's fart smelled like, Monica seemed awfully confident in herself. Monica slightly raises her bouncy ass above your face, "How does it smell?" You take a sniff.
"AAAAAHHhh *COUGH* *COUgh* *cough*; That was NASTY! How the hell did it smell so bad?!"
"Isn't it your turn now?" replied Monica.
"There's no way that I can top that, I give."
"Haha, yes! Because I won, I want you to smell the rest of my farts, they smell god-awful and I don't want to smell them myself."
"Wait, wha-"
Monica quickly covers Sarah's face with her big, squishy bum.
"MMMFFMMFF"
"First one~", Monica grunts. Monica's sweaty ass-hole drove a massive SBD right up Sarah's nose. Sarah's nostrils were flaring, she wanted out.
"MMMMFFMMFFF"
"Second one~", Monica continues. Monica then farted again, forcing you to smell her stink.
"MMMFFMMFF"
"Do you wan't me to stop?"
You open your mouth to answer whe-
Monica's ass-hole drives an even longer SBD in through your mouth, filling your lungs with the horrible stench.
"Works every time! Fourth one~" Monica drives yet another fart into your mouth, which has still not closed. This fart had incredible volume, forcing some of it to come up through your nose, creating an unpleasant experience.
"AAAHHAAHHH"
"Final one~" Monica let out a huge SBD, bigger than the other two combined, it pumps through your respiratory system, driving any other air out of your lungs. You lack the remaining energy to scream in disgust, so you lay there, smelling the curse that is Monica's farts.
Out of gas, Monica bounces on your face, rubbing her ass in, letting you writhe in agony at her farts that she is forcing you to deal with.
Finally, her butt bounces off of your face and Monica stands up, "How was it?"
"It was terrible," Sarah coughed.
"Never underestimate the power of burritos," Monica finished.
"Aah, don't remind me."
"You wanna go ambush one of your sisters?"
"Totally!"
Which sister are you two ambushing?