Make Mia eat Tracy's pussy

You continue your simultaneous motion of forcing Mia down on your cock whilst playing with Tracy's pussy for a while. It isn't long before you can feel yourself getting close to cumming for the third time that evening. You're somewhat surprised that the driver has manged to last so long with Tracy's expert cocksucking lips wrapped around him but then again, she's taking her time with him whereas you're ramming your cock down Mia's throat, or rather the other way round. As you feel yourself approaching your final stroke down Mia's throat you ram her head all the way down on your dick so her lips are shoved into your pubes. You release your seed deep down her throat but she's clearly less experienced in this than Tracy and gags hard on it, spitting some up around the edges of her mouth and a bunch out her nose too. You release your hold on her head, allowing her to finally lift herself off your cock. She gasps for air as she's clearly been struggling to breath through her nose throughout her throat fucking. As she lifts off your cock, long strands of cum connect her nose and mouth to your crotch, which she instinctively wipes away.

As she catches her breath she smiles to you and says "thank you sir."

"My pleasure, now clean up your mess whore."

Mia smiles at this command and begins licking up your cum from her own face and then from around your crotch, making sure to get at every last drop. Clearly her licking your cum off her ass in the alleyway earlier was less about keeping her dress clean and more about her being a cum addicted whore like her sister. Once she finishes licking up your cum she lays her head down on your thighs looking up at you past your now soft cock smiling. Her pretty face is slightly glistening due to the saliva coating around her mouth.

"So tell me whore, are you really gonna do everything I tell you?"

She smiles as she looks up at you and answers "yes daddy."

"Good girl, then I think it's time you eat your sister's pussy."

Mia looks up at you with a shocked expression, but you leave her little time to react as you once again grab her by the hair and lift her head up before forcing her face into her sister's ass. She lets out a muffled squeal into her sister's pussy but after a moment of protesting, slowly starts to accept her fate and ease into it. Tracy has clearly been too focused on sucking the driver's cock and doesn't immediately realise what's going on, instead simply moaning around the driver's cock.

However, after a moment she realises who's eating her out and lifts her head off his cock to squeal out "Oh my god! Mia what are you doing?!"

"She's doing what I told her to, now get back to sucking slut."

"But sir..." You interrupt her complaints by pulling Mia off her pussy and giving her a hard smack on the ass. As you detach Mia's mouth from her sister's pussy a strand of either spit or pussy juice connects her stuck out tongue to Tracy's pussy.

Tracy stops trying to argue with you and returns to her previous task of sucking the cock beneath her head, which you reward by pushing Mia's face back into her pussy. Tracy can't help but let out a soft moan as you do so, indicating her lust is once again getting the better of her. Mia slowly starts getting into her role of pleasuring her sister and uses her hand to start rubbing her clit too.

After a short while the driver pulls up outside your house, but Tracy still hasn't managed to make him cum.

"We're here, but do you mind if your friend here finishes what she started."

"Yeah of course, what's taking so long slut?"

"Shorry shir." After Tracy's response you hear her start gagging on the driver's dick as she forces herself to deepthroat him harder and faster than before. Within seconds he's on the verge of cumming, groaning as he unloads down your girlfriend's throat.

"Oh fuck, that was amazing. Thank you so much."

Tracy lifts herself up off his cock and you release your grip on Mia's hair letting her off her sister's pussy. Mia returns to her seat and Tracy does too, both of them are avoiding looking at each other after what just happened and they remain dead silent too.

"So how much was the trip?"

"For you my friend, free."

"Thank you, that's very generous of you."

With that sorted you open the door to exit the car and let Tracy and Mia out after you. The cab pulls off and Tracy walks towards the house to unlock the front door, followed by Mia, with you close behind. Tracy hasn't bothered to pull down her skirt and her bare pussy which is slick with her own juices and her sister's saliva is out in the night air.