You let them cum.

"Fucking do it." You grin at them lustfully "Cum like the dirty little slut's you are"
Katy grabs hold of Scarlett's head and forces her mouth hard against hers,their tongues explore each other's mouth as their huge tits are pressed tightly together.
As both of them grind their pussy's hard against each other,hips violently flying back and forth,you have no doubt that those clit's are swollen with the ferocity that they are both displaying.
Katy suddenly breaks their embrace and pulls hard on Scarlet's pig-tails.
"You like that bitch??" She shouts in Scarlett's face "You like it rough you fucking slut??"
"Fuck yes!!" Scarlett says grinding harder against Katy's leg "I love it.Fucking use me!!!"
"Yeah you fucking bitch!!!" Katy replies,taking both of Scarlett's tits in her hands and squeezing them as hard as she can "You're my fucking whore now.Fucking say it!!!"
"I'm your fucking whore!!" Scarlett screams out "I'm your little fucking whore who needs to cum so.fucking.hard!!!"
"Good slut" Katy pants now gripping Scarlett's ass and pulling her back in close "Let's both cum together"
You watch in awe as they grind harder now,your cock so solid that the lose of blood to the rest of your body might just make you pass out.
"FUUUUUUUUUUUCK" Scarlett yells,her head buried deep into Katy's chest "I NEED TO CUM"
"THEN FUCKING BEG ME" Katy replies "BEG ME TO LET MY LITTLE SLUT CUM"
"PLEEEEEEEEASE" Scarlett begs,raising her head from Katy's cleavage and looking straight at her as she looks down,her eyes pleading for release "LET YOUR LITTLE.SLUT.CUM"
"FUUUUUUUUCK" Katy screams back at her with a doe wide stare "FUCKING CUM"
You watch as they both throw their heads back,crying out in pleasure as the orgasm hits them at the same time.
"HOLY SHIT" Katy says as she thrusts her pussy violently against Scarlett's knee "FUCK.FUCK MEEEEEE"
"GOD YES" Scarlett replies as Katy grabs hold of her tits one last time and squeezes them as hard as she can "FUCKING YEEEEEEEEEEEEEEES"
You watch in amazement at the spasms that convulse through their bodies,you've never seen anyone cum that hard.
"Oh god!!!" Katy pants as the orgasm subsides "Jesus fucking Christ,that was something else"
Scarlett removes herself from Katy's knee and you can see a wet stain on her stockings.
"Mmmmmmmmm" she sighs,gently kissing Katy on the lips,her face flushed red "That was pretty fucking amazing"
They share one last brief embrace before turning their attention back to you.
"Well stud" Katy grins,her face soaked in perspiration "Did you enjoy the show"
"What do you think" you say looking down at the noticeable bulge in your jeans.
"Mmmmm" Scarlett winks at you "Maybe we should do something about that"